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Using DesignCAD - tips for novices
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January 29, 2015, 08:15:10 PM
DesignCAD's user interface is different from other CAD programs. It is easier to use for most things, but a familiarity with other CAD programs can be a hindrance that makes learning DesignCAD more difficult.

The purpose of this thread is to explain the basic philosophy behind how DesignCAD works. Experienced users can post their tips. Novices can ask questions. I hope everyone will keep posts oriented to new users and try to avoid unnecessary clutter, off-topic rants, and other unessential baggage.

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The program comes with a "DesignCAD Getting Started Guide" to introduce you to the user interface and many of the features of the program. You can find the "DCADXX_GSG.pdf" file in the folder where the program is installed. Note: The "XX" is the version number, like DCAD24_GSG.pdf" for the version 24 guide.

You can find detailed explanations of all the functions in the DesignCAD Reference Manual. You can find the "DcadXX.pdf" file in the folder where the program is installed.

Here is a link to a post about DesignCAD tutorials that will be useful:

http://forum.designcadcommunity.com/index.php?topic=3228.0

                                                                 WHERE DO I START?

This is the first question a new user asks when confronted with a complex program like DesignCAD. Unfortunately, there really isn't a simple answer. You need to know what the program can do. You need to understand something about how the program user interface works. You need to know something about the "design philosophy" behind how the program does things - and what you have to do to get it to do what you want. And then you need knowledge and understanding of each of the command functions available in the program - or at least a small working set to get started.

One nice thing about DesignCAD is that you can jump in and start drawing using the default program settings even if you don't know what you are doing. The workspace is infinite (well, for practical purposes anyway) so there is no setup required. So you can just jump in and start drawing. Later there are a lot of customizable options to make the program work more to your satisfaction, but you really need to try things to learn what you prefer.

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So here is a start. The program opens in 2D drawing mode, like sketching on a sheet of paper.

Press the "V" key on the keyboard - this starts the line (vector) drawing function. Notice that the cursor changes from an arrow to a crosshairs (+) indicating that you are drawing.

Now click the left mouse button - the program sets a point at the cursor position.

Move the cursor (drag the mouse or rotate the track ball) and left click again. Now you have set two points.

Move the cursor again and left click. Now you have set three points.

Press the "Enter" key and you have drawn your first multisegment line in DesignCAD!

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That's the way most command functions work. Of course many are far more complicated, as you will learn as you go along.

Now that you're started, below are some things (but not everything) you need to know to get full use of the program.

Phil
« Last Edit: February 01, 2015, 06:38:34 PM by Dr PR »

Logged
DesignCAD user since 1987


January 29, 2015, 09:05:02 PM
#1
Commands or Functions

You use commands or functions (they are the same thing) to get DesignCAD to do things for you. One of the nice things about DesignCAD is that most commands are interruptible - while drawing you can invoke other functions to change the view, help with setting points, etc.

DesignCAD has several ways to do most operations. You can even customize the program to work more or less like some other CAD program.

1. Menus. The menu system works like any other Windows program. Most are only one or two levels deep. However, some menus (Edit for example) have layer after layer of pull down menu extensions. The organization is mostly logical but you just have to study them to learn where some of the commands are located.

You can create your own custom menus and put whatever commands in these that you want with the "Options/Options/Menu" dialog. See below.

You can open a menu in at least two ways. First and most obvious, just point and click with the mouse/trackball on the menu item. This opens another menu or command dialog.

You can also open a menu from the keyboard by pressing "Alt key" combinations. For example, "Alt V" opens the "View" menu. Then you can execute commands in the open menu by pressing the appropriate key. For example, with the "View" menu open, pressing the "F" key causes the active window display to be resized so all visible drawing objects are visible. The appropriate letter is underlined in the menu element name - "Fit to Window."

2. Hot Keys. Hot Keys are keyboard key combinations using single or multiple key combinations. Many functions have default key assignments as described in the Reference Manual. The assigned key(s) are shown to the right of commands in the pull-down menus.

You can change default keys or create your own custom key combinations with the "Options/Options/Keyboard" dialog.

Note: The hot key for opening the "Options/Options" dialog is the "Q" key. Then click on the "Keyboard" tab to open the Keyboard dialog.

3. Tool Boxes. DesignCAD tool boxes contain tiles for various command functions. Clicking the tile initiates the function.

Some tool boxes have multiple related functions "stacked" on a single tile. A small triangle in the lower right corner of a tile indicates that multiple functions are hidden there. Move the cursor over one of these tiles, press and hold down the left mouse button, and a pop-out tool bar will open to show all of the stacked tiles.

Tool boxes can be dragged anywhere. They can be "docked" to the edge of the screen or left "floating" over the drawing windows.

You can create your own custom tool box and place any command function in it, even those already in other tool boxes.

You can disable any tool box so it doesn't display with the "View/Show-Hide" menu selection, or the "Options/Options/View" dialog.

4. Command Line. If you prefer to do (most) things from the keyboard you can use the "Command Line." Press the Space Bar on the keyboard and the Command Line will open at the top of the screen. Type in the command as described in the Reference Manual.

You can create your own Command Line commands - see the Reference Manual for details.

5. Macros. You can create your own "macro commands" using the BasicCAD programming language. This is an extension of the BASIC programming language with CAD drawing functions. So if there is a procedure that you repeat often you can capture it in a macro.

You can create a macro in two ways:

The simplest way is with the "Tools/Macro Record" command. This is a dialog driven way to record keystrokes in a macro file. See the Reference Manual for details.

You can also write your own macro code in a text editor, give it a "macro_name.dc3" file name and save it in the macros folder (see below). For help with macros and the BasicCAD language look around on the Forum.

To execute a macro press "%" or use "Tools/Macro Execute" and select the macro name from the list. You can execute macros from the Command Line or assign them to Hot Keys, Tool Box icons or Menu items.

NOTE: Macros have one unfortunate side effect. When you execute a macro it will terminate any other function in progress. So if you are setting a series of points for a command and execute a macro, the original command will terminate and all of the set points may be forgotten or the command may terminate with a partially completed object.

6. Custom Program.  DesignCAD has a developers kit for adding program extensions using high level languages like C++. Look around on the Forum for help with this.

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Nested Commands

I may refer to using a function "inside" another function. By this I am talking about starting a new command while you are working with another command. For example, look what you can do while drawing a line (3D mode example):

Start the "Line" command (V)
   Left click to set the first point somewhere in the drawing.
   Start the "Fit to Window" function (Ctrl W)
      The window display zooms out to show the entire drawing.
   Start the "Zoom Window" function (Z)
       Drag a selection box around part of the display using the mouse.
   Start the "Midpoint" snap function (Ctrl K)
       Move the cursor near a line and left click to set a second point on the midpoint of the line.
   Start the "Set Viewer Points" function (View Toolbox button)
       Use the mouse to point to a place in the drawing that you want to look at (The View Center) and left click.
       Press the Enter key to terminate the function.
   Start the "Set View by View Center" function (View Toolbox button)
       Use the mouse to rotate the view so you can see the object of interest better.
       Click the "OK" button at the upper left corner of the screen to end the function.
   Gravity snap to an existing line end to set a third point.
   Start the "Point Relative" function ("Comma" key)
       Enter the X, Y and Z offsets.
       Select the "Last Point" option.
       Click the "OK" button to close the dialog.
       A fourth point is set relative to the last point.
   Press the "Enter" key to end the "Line" function.
The program goes back to waiting for your next action.

See how a bunch of other functions were used to assist with the use of the "Line" function? These intermediate commands were nested inside the "Line" function. You don't have to set up a single view for all the points, and you can use the point setting functions to assist the "Line" function. Most drawing commands work this way. However, you cannot use macros inside other functions. The execution of a macro terminates any other function in progress, and you may loose any points that you have set previously.

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Status Bar

At the bottom of the screen is the Status Bar. Information about program operation and command progress is displayed here.

When you start execution of a command you will see prompts telling you what to do at the left end of the Status Bar. It is a small space so some of these prompts are pretty cryptic, but they can help beginners get used to using the commands. And even experienced users may need help with the less commonly used functions.

At the right end of the Status Bar are several boxes that tell you something about program operation.

Drawing Base Units. Drawing units are whatever measurement units you have assigned, such as inches, millimeters, furlongs, whatever. In other words, it tells you what a distance measurement means - ten what? The program defaults to a "Unitless" mode with no assigned units of measure.

You do not need to assign any units to draw. In fact, I have been using the program since 1987 and I can't recall ever assigning units to a drawing. They are irrelevant to the drawing process, because whatever units may be used a line that is twice as long as another line is twice as long in all units.

However, if you are going to export your drawing to another program that does require base units it is a good idea to make the intended drawing units a part of the file.

Snap Mode. This indicates whether the "Running Snap" mode is disabled or enabled - it defaults to disabled. If you enable "Running Snap" the snap mode indicator changes from "OFF" to "RS."

Running Snap mode displays potential snap points (end point, mid point, etc.) as you move the cursor close to an object while a drawing function is operating. Snap points are indicated by a small square at the point. All you need to do is place the cursor over the square and left click to snap to the point. This is very convenient. However, in large drawings it brings the program to a crawl, and sometimes to a complete stop because there are so many potential snap points. Even on the fastest computer it can take tens of seconds to display each potential snap point as you move the cursor.

Number of Points. This tells how many points you have set while using a drawing function.

Zoom Factor. The zoom factor relative to something. The initial empty drawing window zoom factor is 100% but this changes as you work on the drawing.

Display Mode. This tells what display mode you are using (2D Drafting, 3D WIREFRAME, 3D HIDE, 3D SHADE, etc.).

Preset Point Mode indicator. This is normally shaded out. If you activate Preset Point Mode (see below) if will show "PRESET PT" in black letters.

Work Plane. You normally work in the default work plane using the X, Y and Z axes. However, you can create custom work planes (View/Working Plane/Set Working Plane) that are angled with respect to the default work plane. This can be very useful when you are trying to create objects that are oriented with respect to a slanting surface.

If no custom work plane is active this displays "DEFAULT WP." If a user defined work plane is active it displays "UCS-n" (User Coordinate System #n). You can define many custom work planes in a drawing and switch between them and the default work plane.


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Preset Point Mode

The default DesignCAD drawing mode requires you to select a drawing function (Line, Curve, Box, Cylinder, etc.) and then place a sequence of points to define the object. Then you either press Enter or activate another drawing function to end the operation and cause the object to be created.

You can reverse the sequence by selecting the "Options/Preset Point Mode" menu item. When selected the background behind the tool icon will be darker gray and look like a button is pressed.

With preset point mode you first place a sequence of points and then select a drawing function. The object will be drawn immediately with no other key press or mouse operation. This typically requires one less keystroke (no need to press Enter) that the default mode.

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Program Customization

Your custom keys, menus, tool boxes, macros, materials, etc. are saved in separate files. The locations of these files are listed in the "Options/Options/File Locations" dialog.

THIS IS IMPORTANT

The program puts files in a default location that is different for each version of the program. When you update the program the new version will not remember where you put all of your custom keyboards, tool boxes, menus, etc.

I recommend that you create your own folder to keep these files, say:

C:\DesignCAD

or whatever. I usually keep the keyboard definition, custom tool box and custom menu files in this folder. I keep macros in:

C:\DesignCAD\Macros

Then, when I install an upgrade I use "Options/Options/File Locations" to point DesignCAD to my custom features.

Also, when you make changes to how the program operates or create a custom file, such as the custom keyboard, you may need to click an "Apply" button to make the changes take effect - otherwise they may be ignored. Furthermore, you must click a "Save As Default" button to make the changes carry over to future uses of the program. AND, in many cases these default changes are not recorded until the program is closed. If the program crashes or you turn off the computer before closing the programs your changes will not be remembered.

Phil
« Last Edit: March 06, 2016, 10:50:36 AM by Dr PR »

Logged
DesignCAD user since 1987


January 29, 2015, 09:47:22 PM
#2
2D and 3D

The 2D program works like drawing on a sheet of paper. This is pretty simple and intuitive. You work in two geometric dimensions (width and height) to add lines, hatches and such to create, save and print a flat line drawing.

The program has many 2D drawing functions. You should read through the Reference Manual and practice using the commands to learn how they work.

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The 3D program creates a virtual 3D universe in the computer's memory. For many people this is very non-intuitive, especially if they have previous experience working with a 2D CAD program. You really need to forget everything you know about 2D drawing and start over.

3D CAD is very much like playing with modeling clay, except you can't actually touch the clay. You have to learn how to tell the program to shape the clay and show you what the clay looks like. It is very inconvenient and non intuitive at first.

First of all, 3D drawings are composed of 3D objects like planes (filled polygons) grids and solids. These are virtual representations of real world objects, and in most cases the goal is to create solids that mimic real world things, like cabinets, machined metal pieces, houses, ships, airplanes, whatever. The larger assemblies are made up of many smaller pieces, usually solids.

However, DesignCAD will allow you to create 3D objects that are impossible in the real world. A plane (filled polygon) is a good example, it has length and height but no thickness. A "grid" is a curved surface that has no thickness. Grids are composed of many filled polygons linked together in a single object.

You can draw simple lines, curves, circles, etc., but in 3D space you always have a third dimension to deal with. It is best to work with planes, grids and solids as much as possible and avoid the basic 2D objects like lines and circles when you can. For more information see the "Object Types" discussions.

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With DesignCAD there are two general types of solids, "proper" and "improper." Proper solids are composed only of planes and grids, are fully enclosed, and have no extraneous internal pieces such as extra planes or multiple planes coincident with each other. They have no "leaks" or openings between the inside and outside. Proper solids are essential for 3D printing!

Improper solids have leaks or openings, and may include 2D objects like lines, curves, circles, etc.

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There are two fundamental ways to create 3D solids.

Additive. You create 3D objects like planes (polygons) and grids and assemble them into closed assemblies. Then you use "Solids/Solid Define" to bless them and make them into a solid.

You can also combine multiple solids into a single solid, either by just selecting them all and defining them to be a solid with "Solid Define," or with the solid Boolean functions (Solid Add, Solid Subtract, etc.).

And you can combine solids, lines, planes, grids - whatever - into a new single solid with "Solid Define."

You can define ANYTHING to be a "solid" in DesignCAD. For example, you can assemble five squares into an open topped box and define it to be a solid. You can define lines to be solids. BUT, these improper solids do not always work correctly with some of the solid editing functions. With this method it is the responsibility of the user to ensure the solid is complete, with no leaks between the inside and outside.

One of the major sources of confusion for novices is the failure to understand the difference between a bunch of entities  lumped together and called a solid and a true proper solid. Improper solids are guaranteed to cause you problems with some of the editing tools, so they should be avoided.

Subtractive. This method is like working with a milling machine, removing bits and pieces from a "work piece" solid.

You create a "tool" solid that is the shape of the part you want to remove from the work piece. Then you use "Solid Subtract" to cut away part of the work piece. For example, to "drill" a hole you create a drill bit tool (a cylinder). You place the tool correctly relative to the work piece and subtract it from the work piece.

IF the tool and work piece are proper solids the result will always be a proper solid.

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Most people use both methods, depending upon which is faster. In some cases figuring out how to shave off complex shapes with the subtractive method is a real mind bender and it is much simple and quicker to build up a bunch of planes and grids one at a time and then lump them together with "Solid Define."

Phil
« Last Edit: October 23, 2015, 01:31:54 PM by Dr PR »

Logged
DesignCAD user since 1987


January 30, 2015, 01:21:57 AM
#3
Viewing Your Work.

You need to see what you have drawn in order to work with it. For this you need to know how to tell DesignCAD to show you what you want to see.

Windows

Each drawing window has a name that is shown in the title bar at the top of the window (if there is more than one window). The default name for the original window is "main."

In 2D mode each window shows part or all of the flat drawing. In 3D mode each window is a view port into the virtual universe inside the computer.

DesignCAD defaults to a single large drawing window in 2D and four windows for 3D, but you can have as many windows as you need to view your work. For example, suppose you are working on a drawing and want to connect distant points with a line. What if the desired points are located in a clutter of other points?

You can zoom in at one place and start the line by snapping to the desired starting point. Then zoom out to view the entire drawing, and then zoom in to view the end location and snap to the desired end point. This is OK if you want to draw only one line, but what if you need to connect a lot of distant points?

You can open a second (and third) window with the "Window/New Window" menu option. You select each window by left clicking in the title bar at the top of the window, or just by clicking anywhere in the window. Then you can zoom in in each window to get a magnified view of the end point areas. Now you can place the cursor in the starting end window, set a point, move to the end view window and set a second point to complete the line.

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Change The View

You can use the horizontal and vertical scroll bars at the edges of the "main" window to "pan" the view left/right and up/down (if you haven't hidden the scroll bars with "View/Show-Hide").

If you hold down the CTRL and ALT keys while moving the cursor the view will pan to match cursor movement.

You can enlarge or reduce the view in a window by "zooming" in/out. There are several ways to do this, depending upon which you prefer.

The "View\Zoom" menu has options for "Zoom In," "Zoom Out" and "Zoom Window." You can also change the "Zoom Factor" - this is how much the view in the window will be magnified or shrunk.

"Zoom Window" allows you to drag a selection box around the part of the view that you want to enlarge to fill the window.

You can also use the buttons at the lower right corner of the "main" window in the vertical scroll bar to zoom in and out.

The mouse wheel will pan the view up/down, and if you hold down the Shift key it will pan left/right. If you hold down the CTRL key the mouse wheel zooms the view in/out.

The "+" and "-" keys work to zoom in and out, but not immediately. Each press sets a zoom count, and then you press the "Enter" key to execute the zooms. The program remembers every key press and there is no way to cancel them all - you have to press the Escape key repeatedly to cancel them one at a time. This is sort of screwball and very inconvenient.

The "View/Fit To Window" (CTRL W) function expands/contracts the view so all parts of the drawing fit into the window. CTRL Shift W fits the view in all open windows.

Occasionally something causes the view to be incomplete - say you press the Escape key while the view is redrawing to stop the redraw. When this happens the "View/Regenerate" (CTRL R) function will redraw the view in the active window. "Regenerate All" (CTRL Shift R) redraws all open windows.

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Rotate The View

When working in 3D it is handy to be able to rotate the view so you can see the back side of things or just move the view a bit to make it easier to see. This does not work in 2D mode.

Hidden line and some shaded views will rotate if "Enable graphics acceleration" is enabled in the "Options/Options/View" dialog. If it is disabled only wireframe views rotate (see below).

Note: In versions 24 and later graphics acceleration is automatically turned on for OpenGL shading.

Rotating the view is not the same as rotating an object. When you rotate objects ("Edit/Selection Edit/Rotate" or "R") they turn relative to the workspace axes. When you rotate the view the object stays put (it's orientation relative to the drawing axes doesn't change) and the "camera" moves relative to the workspace.

DesignCAD uses a "jeweler's view" system, where the view rotates around a point inside the drawing. This is very different from an architect's view from inside the drawing looking out! The resulting view is projected onto the drawing window.

There is a "View Center" that the "camera" is always pointing toward and a camera position. You can change these with the "Set Viewer Points" function in the View Toolbox (black camera with red arrow). If you set just the first point with this command it changes only the View Center.

DesignCAD has two view rotation functions, both selectable with buttons in the View Toolbox. After starting the function, when you move the cursor the view rotates in the opposite direction of cursor movement. The cursor actually moves the camera around the objects instead of rotating the objects in front of the camera. DesignCAD's view rotations will rotate left/right and up/down, but they are far less sensitive than most CAD program's view rotation functions so they are much easier to control for fine view changes. To end the view rotation click the "OK" button the the top left of the screen. Click "Cancel" to return to the original view before rotation.

"Set View By View Center" rotates the view around the view center, even if the View Center is not in the view shown in the window. If you do not set the View Center first the objects you are trying to view will likely spin out of the view.*

"Set View By Drawing Center" rotates the view around the geometrical center of all visible drawing elements, regardless of where the View Center is located within the drawing. If you are zoomed in it is likely that what you want to look at will disappear off screen.

*The "vc.d3m" macro (available on the Forum) first allows you to click on a position/point in the drawing and then initiates the "Set View By View Center" function. This causes the objects you are interested in to stay at the center of the screen as you rotate the view. Unfortunately, since it is a macro, you cannot use it "inside" another function. When you start a macro it terminates any other function in progress.

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3D View Types

The program has several preset view types. These only set an initial view. You can rotate the view in any window after setting it so the original view is no longer seen.

"Front View," "Side View" and "Top View" show views looking down the Z, X and Y axes respectively.

"Isometric View" rotates the view 45 degrees around all three axes.

"Parallel View" displays the view with no perspective so parallel lines/sides are displayed parallel.

"Perspective View" shows the drawing with perspective distortion. Things closer to the camera are displayed larger than equal sized objects more distant.

Perspective view uses a "View Distance" from the camera to the view point to control the distortion. You can change View Distance with tools in the View Toolbox. You can type a number directly into the View Distance box or you can use the "Increase View Distance" (down arrow) and "Decrease View Distance" (up arrow) to change the perspective distortion.

CAUTION: In most cases the View Distance should always be several times as great as the largest distance across the drawing. The default value of 1000 may be much too small! If the View distance from the camera to the View Center is shorter than the dimensions of the drawing some objects may rotate behind the camera and disappear from view. However, if you are trying to accomplish an architectural "walk through" you may want the View Distance to be short, but it can cause weird perspective distortions.

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Wireframe and Shading Views

2D drawing mode has only wireframe views. Simulated shading can be accomplished with Hatch patterns (Draw/Hatch/...).

3D drawings offer several viewing options. In V24 and later there are two basic modes, GDI and OpenGL. In V23 and earlier you select "Enable graphics acceleration" to enable OpenGL modes.

GDI mode produces shaded images with all light and shadows (if enabled). However, if you try to rotate a GDI image the view reverts back to wireframe.

OpenGL display uses special software developed for CAD drawings that allows shaded drawings to be rotated.

The program uses graphics acceleration code to produce rotated shaded and hidden line views. This is available only in OpenGL mode. Normally the program does not use special graphics hardware on the video card (see RedSDK below).

Wireframe is pretty much the same as a 2D line drawing, but in 3D. You have the options to show everything or to show only objects that do or do not shade (renderable objects).

In some shading modes simple 2D objects like lines are not visible. In other shading modes they appear as bright streaks. If you disable the "Wireframe Renderable Objects" option all planes, grids and true solids will disappear, allowing you to see any non renderable objects in the drawing.

Hidden line shows a wireframe view with all parts that lie behind renderable surfaces hidden from view. You have the option to make the hidden lines display as dashed lines. It is available in GDI and OpenGL modes. With graphics acceleration enabled you can rotate the hidden line view, and you can display the intersections of surfaces.

Quick Shading (flat) displays a roughly shaded image of the drawing. Individual facets of grids are shown flat with no attempt to produce smoothly shaded curved surfaces. This is a very fast shading mode. It is available in GDI and OpenGL modes.

Gouraud shading produces a nice smooth shaded image. It is available in GDI and OpenGL modes. In OpenGL mode the shaded image can be rotated. In GDI mode shadows will be displayed if they are enabled. Texture mapped images are not displayed.

Phong is the highest quality shading method, and the slowest. It is available only in GDI mode. Phong shaded images cannot be rotated. Phong used material textures and shadows (if they are enabled). Only with Phong shading can you get true colors and really black blacks and bright whites.

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3D Lighting

Lighting is controlled from the "Options/Options/Light Source" dialog.

You can select several different light types.

The "Directional Light" is from a source far away, like the sun. You can set the horizontal and vertical angles. These angles are normally relative to the drawing, but if you select the "Move with eye" option the angles are relative to the view direction from the camera to the View Center. This is useful for simulating a light source that follows the camera.

A "Point Light" has a position within the drawing and radiates in all directions from that point.

The "Spot Light" originates from a point in the drawing and can be aimed at another point in the drawing. You can control the angle of the light cone.

You can set the color of the lights.

DesignCAD has a weird schizophrenic way of dealing with lights and object properties - see Color and Materials below. There are three sliders in the Light Source dialog for "Ambient," "Diffuse" and "Specular " intensity.

The Ambient slider controls how much background light there is, like light reflected from other objects, or skylight. I normally leave this at 100%, but lesser values can create "mood lighting" effects, like dawn or dusk.

Diffuse and Specular effect how light reflects off of objects. This should be controlled only by the objects's material properties (see below). But in DesignCAD you can change an object's appearance from shiny to dull by fiddling with the light source! That is just bizarre. I normally set these sliders to 100% so the material properties will determine if an object is shiny or dull.

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3D Shadows

Shadows are useful for creating a more realistic scene, and for distinguishing overlapping parallel objects that would otherwise all display with the same shading.

Shadows can be enabled in the "Options/Options/Light Source" dialog with the "Shadows On" option. This produces a crude shadow effect by creating a shadow map of the entire drawing, not just what is displayed in the window.

Open the "Shadow Options" dialog to select shadow options.

The "Shadow Map" slider lets you choose the "graininess" of the shadows, from 128x128 to 2048x2048 shadow "chunks." Basically, this divides the entire drawing area into "tiles," and the average shadow for the tile area is created. 128x128 is very low resolution and 2048x2048 is better, but marginal at best.

This has nothing to do with the resolution of the display - even on very high resolution images shadows can be very "jaggy." Say the drawing is 10,000 drawing units (inches, mm, furlongs, whatever) wide. The 2048x2048 shadow map will produce shadow tiles about 4.9 units across. At full zoom the shadows may look OK, but if you zoom in to view a part of the drawing only 100 units across there will be only about 20 shadow tiles, even if the display is 1900 pixels wide. At this zoom level shadows look horrible!

"Shadow Softness" determines how dark the shadow is, or how much detail is visible in the shadows. A value of zero produces totally black shadows with no visible details in the shadows. A value of 1.0 produces no shadow at all. Values of 0.3 and 0.4 produce distinct shadows with visible details.

"Shadow Tolerance" is something of a mystery. I don't know what it is supposed to do, but it has the effect of causing the shadows to wander away from the objects casting the shadows. A value of 0% produces the best shadows.

New/old shadows. The original shadows cast strange parallel lines behind long narrow objects. If "Options/Use New Shadows" is enabled the shadows cast by long narrow objects will look more natural.

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Color and Materials

In 2D objects have a base color only. You can set this color two ways. First, an object is drawn in the current color that is selected in the Color Toolbox. If you change the current color new objects will then be drawn in the new color (existing objects retain their assigned color). Second, you can select an object, open the Info Box (CTRL I) and click on the color tile near the upper left corner of the dialog. Select a color from one of the options or click in the color palette. You can type in a RGB color scheme if you want an exact color. Click OK to save the new color.

Layers can have assigned colors, and these override the base color. This is a topic for another post.

In 3D objects have materials, and this is a major difference from 2D drawings. 3D objects can have two colors, a base color and a material color. Objects are created in the "Default" material if no other material is selected. The Default material has only a base color.

Other materials can have inherent material colors, and even texture patterns like wood grain, rock grain, etc. When you assign a material like "Brass" or "Aluminum" to an object it has a material color and a base color appropriate for the material. However, you can select the object and assign a different base color with the Info Box as described above. In wireframe the base color is displayed, but in shaded modes the material color will be displayed IF the "Enable color material" option is selected in the shading dialog. If it isn't the base color will be used.

This dual color feature can be very useful. For example, in wireframe mode objects with the Alumunum material display very light gray, almost white, and they are difficult to see with a white background. But if you assign a different base color, say red or black, they can be seen easily. Then when you generate a shaded view they will display the Aluminum color (if the "Enable color material" option is selected).

Materials can be transparent like glass and they can have texture patterns. Read the Reference Manual to learn about all the options.

You can also apply bitmap images to objects with the "Tools/Texture Mapping" function. This allows you to "paint" a bitmap image, like a photograph, onto a surface. Again, read the manual to learn about the options.

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Printing and Image Creation

Printing (File/Print) is pretty straight forward. If you print a shaded drawing it will not be exactly like what you see on the screen. It is something like a Phong shaded image.

You can save image files with "File/Image/Save Image File." First drag a selection box around the part of the image in the window that you want to save (or press Enter to save the full window image).

In the "Save Image As" box select the type of image.

"Current Display" saves the image in the window with the same number of pixels as on the screen. This is a pretty low resolution image.

"Wireframe," "Hidden Line Removal" and "Quick Shading" create images as described above.

"Smooth Shading" produces an image similar to Phong shading, with shadows if they are enabled.

You can select an image size up to 10000x10000 pixels - the width or height will be adjusted to maintain the same image aspect ratio as the area selected on the screen.

Note: With "Current Display" even if you select a large number of pixels the image will still have the same resolution as the screen - screen pixels may be mapped into square blocks of pixels in the saved image file.

Note: In V24 and earlier you must have graphics acceleration off to save an image. This means the screen display must not be OpenGL. It can be wireframe or Phong shaded. If graphics acceleration is enabled you will get only a corner of the selected area in the image. This bug was fixed in V25.

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Paper Space Mode

Paper space is a printing mode that allows you to compose several 2D and 3D views on a single drawing sheet. You edit the drawing in the normal 2D/3D workspace and switch to paper space to compose a 2D image.

This is a complex subject that fills five pages of the Reference Manual. Perhaps someone more experienced with it than I will post a description of how to use paper space.

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RedSDK

DesignCAD is in a state of change. All of the display options I have mentioned above are carry overs from the dark ages of MS/DOS and Windows 3. They have been updated over the years, but are pretty primitive compared to many other programs' rendering capabilities. That is about to change!

The programmers are busy incorporating a new display package called RedSDK. This is still in the beta testing stage (2015) so I won't go into detail. But the whole RedSDK package has advanced features like ray tracing that allow photo realistic images to be produced with reflections, shadows and other sophisticated effects. Stay tuned!

Phil
« Last Edit: October 23, 2015, 02:01:25 PM by Dr PR »

Logged
DesignCAD user since 1987


January 30, 2015, 01:34:45 PM
#4
Selecting Objects

Before you can edit something you have to select it. There are numerous ways to do this in DesignCAD.

1. Just move the cursor over an object and left click to select it. When selected the wireframe outline of the object will turn pink/purple (the default color - you can change this in the "Options/Options/Color" dialog).

2. Gravity snap to a point on an object. Gravity snap is one of DesignCAD's most powerful features. You can gravity snap by:

  a. Moving the cursor near an object and pressing the comma (,) key - the cursor moves to the nearest point.

  b. Moving the cursor near an object and pressing the period (.) key - the cursor moves to the nearest point and sets a point.

  c. Moving the cursor near an object and click the right mouse button - the cursor moves to the nearest point and sets a point IF right click gravity snap is enabled.

Note: The default program behavior is for the right mouse button to open a pop-up menu of actions that are appropriate for the situation. The first option on this menu is "Use Right-Click For Gravity." Select this option to make right click gravity snap the cursor to the nearest point. You can also open "Options/Options/General" and disable "Enable right click popup menu."

When right click is enabled for gravity snap, holding down the CTRL key while right clicking will bring up the pop up menu.

If there are multiple objects where you click or gravity snap the object that you are interested in may not be selected. In this case just press the Enter key to select another object. Repeat until the correct object is selected.

3. You can move the cursor to one side of an object(s), press the left mouse button and drag a selection box around the objects, then release the left mouse button to select everything. All items that were completely enclosed in the selection rectangle will be selected.

However, if you press the CTRL key before releasing the left mouse button all objects within the selection box or partially enclosed (touching the selection box) will be selected.

4. The "Edit/Select All" (CTRL A) function will select everything that is visible and on unlocked layers (see the Layers discussion thread).

5. The "Edit/Select Previous" (Shift P) function will reselect all of the previous selection. For example, suppose you want to add something to an existing group. Select the group and the new object, and explode the group with the "Tools/Group/Group Explode" function. After this nothing will be selected. Now use "Select Previous" to reselect all of the parts of the exploded group plus the new object. Now use "Tools/Groups/Group Define" to create a new group with all the parts of the old group plus the new part.

6. To deselect everything that is currently selected press the Escape key.

You can also just move the cursor to an empty part of the screen and left click. However, DesignCAD will search for anything near the cursor point - for this it must examine every point on every object in the drawing. In very large drawings this can take a long time - in the meantime the program is unresponsive (hey, you told it to look, and it's looking!). So it's best to use the Escape key.

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Selection Modes

OK, all of that was pretty straight forward. Now take a deep breath, let it out, and relax. How you select things can be a bit more complicated.

2D Selection Mode. In 2D drawings this is the only mode. The cursor moves on the plane of the drawing, so left click selects the nearest object and gravity snapping move to the nearest visible point.

But you can use "2D Selection Mode" in 3D drawings - in fact, this is the default selection mode. The program uses the screen image like a sheet of paper, and the cursor position is on the screen surface. When you left click or gravity snap the nearest visible object or point on the screen is selected. However, in 3D all objects are not at the same depth into the view. So you may select or snap to objects/points that appear close to the cursor on the screen but are actually far from the screen in three dimensions (depth into the view). In other words, when clicking to select objects the depth into the view between the cursor and objects is ignored. This seems to be the most intuitive way to work and most users prefer to use it.

3D Selection Mode. In this mode the cursor position is not on the screen, but is at some depth into the drawing. When you left click or gravity snap the program looks for the closest object at the cursor's depth. This may not be the object that appears to be the closest to the cursor on the screen.

"3D Selection Mode" allows you to restrict the select/snap operations to objects at or near to a specific depth in a drawing. In very crowded drawings with bazillions of objects and points everywhere, this may be the easiest way to steer through the drawing to select what you want. However, it is not very intuitive and takes a lot of getting used to.

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Point Select Mode

This is an extremely powerful way to edit existing objects. Normally when you select an object the wireframe outline is highlighted. If you enable Point Select Mode all of the points in the selected object will be marked with small squares. Press the "CTRL 1" key combination to toggle Point Select on/off.

Point editing. Once Point Select Mode is on you can move and edit individual points in an object. For example, say you want to move a point in an existing object. Select the object and move the cursor over the point - the cursor changes to a "target" icon. Now left click and drag and the point will move with the cursor. You can use some of the cursor movement functions (another topic) to move the point precisely.

What if you want to move a bunch of points the same distance and direction - say to stretch an object? Press the left mouse button and drag a selection box around the desired set of points, and release the mouse button. The selected point boxes will become little black squares. Now move the cursor over any one of the selected points and click the left mouse button - this selects all of the highlighted points. When you move the selected point all the other highlighted points will follow, keeping their same orientation to the selected point. For example, you can select a cylinder, drag to select all of the points on one end, and then select a highlighted point and move it some distance to stretch the cylinder.

After you select a bunch of points you can add more points to the selection by pressing the Shift key and either clicking on individual points or dragging another selection box around several other points.

Adding and Deleting Points. When you move the cursor over a selected object in point select mode the cursor may change to show a "+" inside the arrow. This means you can left click to create a new point on the object. Suppose you have a line, curve or plane, and you want to add a point to it. Just move the cursor near the desired position (between other existing points) and when the "+" appears left click. This adds a new point to the object, and the point follows the cursor. Left click again (or use any of the cursor positioning tools) to place the point.

To delete an existing point hold down the Ctrl and Shift keys and move the cursor over the unwanted point. When the "-" appears in the cursor left click and the point will be removed.

Cutting Objects. If you press the Ctrl key the cursor turns into a scissors icon when you approach a part of a line or curve not near an existing point. If you left click the line or curve will be cut into two parts. Note: If this isn't what you intended immediately use "Edit/Undo" (Ctrl Z) to restore the drawing as it was before the cut.

Moving The End Of  A Line. If you hold down just the Shift key while you move the cursor near the end of a selected line three small dots appear at the end of the cursor. Now if you press the left mouse button you can drag the end point of the line farther away from or closer to the nearest point - the point slides along the existing line. When you release the left mouse button the point stops where you dragged it.

CAUTION

Using Point Select mode in 2D drawings is "safe" in that it does not corrupt the drawing. However, in 3D drawings Point Select mode will allow you to corrupt a drawing so that it may no longer be useable.

DesignCAD creates planes and grids with all points in a geometrical plane. Each plane has one and only one "surface normal" (a perpendicular to the facet/plane) for the entire plane/facet surface. Point Select mode allows you to select a point of a facet/plane and move it out of the plane of the other points. This creates a plane/facet with more than one surface normal.

THIS IS GUARANTEED TO CAUSE PROBLEMS

These warped planes/facets will cause the solid Boolean functions (Solid Add, Solid Subtract, etc.) to do strange things and create improper solids. Warped planes/facets display with multiple tones creating a kaleidoscope effect, and they cast shadows in strange directions, causing shadow spots to appear where they should not be.

It is up to the user to ensure that planes/facets are not warped when using Point Select mode.

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Selection Filter

Suppose you want to select some or all objects with a particular characteristic such as color, entity type, layer, line type, etc. If you open "Edit/Selection Filter" (Shift F) the dialog allows you to enable the selection type by checking boxes in the lower left part of the dialog. For example, you might enable "Select by Color" and "Select by Entity Type."

Then click on the "Color" tab at the top of the dialog box. The window on the left will show all colors of all objects in the drawing. Just left click on a color tile and then click the "Add --->" button to move it to the right side window. Then click the "Entity Type" tab. The left window shows all entity types in the drawing. Select the type you want and click "Add --->" to move the type to the right window.

Now, with the Selection Filter dialog still open, move the cursor to the drawing window and use any of the selection methods described above to select the desired object(s). You can use "Select All" to chose every object with the desired features, or drag a selection box around part of the drawing to select all objects with those features in an area of the drawing.

When you close the Selection Filter dialog the filters are disabled and you go back to normal selection modes. This can be confusing because some programs use selection filters that remain active after the dialog is closed, and you must reopen the dialog to cancel the filters.

Phil
« Last Edit: October 23, 2015, 02:10:21 PM by Dr PR »

Logged
DesignCAD user since 1987


January 30, 2015, 02:20:42 PM
#5
Changing Object Properties - The Info Box

When I started using DesignCAD I was frustrated because it didn't have a "change layer" function, or a "change color" function. What if I wanted to change line types? Did I have to redraw everything?

Then I discovered the Info Box. It allows you to do almost anything to an object, all from a single dialog! No more messing around with menus! This happens to be one of DesignCAD's most powerful features.

First you must select an object or objects. Then you can open the Info Box from the "View/Info Box" menu, by pressing "Ctrl I" or from the tab at the right side of the screen (if "Panes" are enabled in "View/Show-Hide"). Or just double left click on an object to open the Info Box.

The Info Box contains all sorts of information about the object or objects selected. You get more detailed information if a single object is selected. For example, the box at the top of the dialog tells what layer the object is on and some details about the state of the layer (current, locked, etc. - see the "Layers" discussion). If several objects are selected that are on different layers the box will say "Multiple."

The Layers box has a pull-down layers list that shows several layers (you will have to scroll down to see all layers). Enable the "Occupied layers only" option right below the box and the pull down layers list will show only the layers occupied by the selected objects.

The Info Box normally stays open only as long as an object is selected, and closes when all objects are deselected. But you can force it to stay open all the time by clicking the black "push pin" button at the right  end of the tool buttons near the top of the dialog (works only if Panes are disabled). If panes are enabled click the Info Box tab at the right side of the screen and then click the little push pin icon at the upper right corner to keep the dialog open even when objects are not selected. Having the Info Box open all the time wastes screen space when it isn't needed and slows the program down quite a bit in large drawings, but it can be a good way for novices to learn about objects while they work with them.

Change Layers. You can move the selected object(s) from one layer to another by selecting the desired layer from the drop down list at the top of the dialog. Just click on the new layer number/name and the object(s) will be moved to the new layer.

Change Colors. The color tile button at the left end of the tool buttons near the top of the dialog shows the selected object's current base color. If several objects with different colors are selected the button will show an artist's pallet.

Click the color tile button and the "Color" dialog opens. It has a selection of predefined (default) colors on the left, and a rainbow hued color palette on the right. Below this on the left is a Custom Color Table where your own custom colors are shown.

Click anywhere on the color tiles or palette to pick a new color. The color box at the lower right shows the selected color, and the RGB (Red, Green, Blue) color numbers are shown beside it. If you want an exact color you can type in 0-255 values in the appropriate color number box.

A slider at the right of the color palette allows you to change the hue of the selected color from black to white.

When you have the desired color just click the "OK" button and the selected object(s) will have the new base color (this does not change a material color - see below).

You can also save your new color in the custom color table with "Add to Custom Table." To make these custom colors permanent you must save them with the "Save Colors to File" button, and then reload them when you need them with the "Load Colors from File." If you click "Save as Default" the program will automatically load your custom color file when the drawing is opened. The "Reset" button resets the DesignCAD default colors.

Change Materials. Solids, grids and planes all have materials in addition to a base color. You can change the existing material by opening the "Material" drop down list. DesignCAD has several predefined materials, or you can create your own custom materials (subject for another post). Just select the desired material from the list and the object's material will change.

This may also change the base color shown in the color tile at the upper right of the Info Box. However, you can change the base color to any color as explained above for changing colors. When you do this the new base color will display in wireframe display mode and the material color will display in shaded images (if Enable color material is selected - see the "Viewing Your Work" post).

Object Information. The rest of the Info Box contains information about objects, such as XYZ dimensions, line lengths, line type and scale, etc. You can change the values in some of these information boxes to change the size and shape of objects. The information is specific to the object, and may fill two dialog boxes.

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Learn to use the Info Box!

Phil
« Last Edit: October 23, 2015, 02:20:10 PM by Dr PR »

Logged
DesignCAD user since 1987


January 30, 2015, 02:51:03 PM
#6
Using Handles

Have you noticed that when you select an object one or more dots or circles appear on or around the object? These are "handles" and they are one of DesignCAD's most powerful features. An object can have up to three handles.

The Primary Handle. When you move an object it is dragged by the primary handle (the large blue dot). Wherever you click to place the object, the blue dot will go there and drag the object with it.

If you select an object with a selection box the primary handle will be positioned near the center of the selection box, and this may not necessarily be on or near a particular object. When objects are created DesignCAD follows program rules to set handles, and this may not be where you want them. So how to you change the position of the handle(s)?

Select an object and use "Edit/Selection Edit/Set Handles" (Ctrl H) to open the small "Set Handles" dialog box. The drop down list includes many default handle locations, but the default "Any location" option is the most versatile.

Just left click or gravity snap to set a new primary handle and press Enter. This places one handle on the object. Now when you move the object this handle will go wherever you set it and the object will be positioned relative to this handle. For example, if you set the handle on a point of the object, then drag the object and gravity snap to a point on another object, both points will be coincident. The moved object will be contacting the second object.

Multiple Handles. OK, why would you want two or three handles? What are they good for? Let's suppose we have a plane that is inclined at some unknown angles, and we want to place a cube so that one face of the cube rests on the plane. Well, if you are good at geometry and trigonometry you can pull out your calculator and do the math to figure out how much the cube should be rotated around the X, Y and Z axes - after you have determined what angles the plane lies in relative to the three axes. And after you have dug out your old math texts (you do still have them, don't you) or searched the Internet for help.

OR

You can select the cube and place the prime handle at one corner of the base (the origin for the cube), another along one side of the base (one axis for the plane) and a third handle at another point on the base of the cube (to define the base plane for the cube). Select the cube and start the "Edit/Selection Edit/Move" (M) operation. Now click on three points around the plane and the cube will be positioned with the prime handle/corner at the first point, it will be rotated around the prime handle so the second handle will be oriented toward the second point, and the third point will rotate the cube around the prime-second handle axis so the base lies flat on the surface of the plane.

Do the math or just click, click click to position the cube. Which would you rather do?

Multiple handles allow you to draw an object with sides orthogonal to the normal working plane and then rotate them through arbitrary angles without having to know what those angles are. Learn to love them!

Phil
« Last Edit: October 23, 2015, 02:25:17 PM by Dr PR »

Logged
DesignCAD user since 1987


January 30, 2015, 11:56:31 PM
#7
Layers

Originally layers were added to CAD programs to emulate the stacks of clear plastic overlays used for 2D drawings of things like multistory buildings, maps and printed circuit board layouts. Layers are mainly a visibility control, allowing some things to be made invisible to reduce clutter while you were working on other layers. But layers can also be used to organize the objects in your drawing and to control how they are displayed. Layers work the same in both 2D and 3D drawings.

You create and control layers in two ways in DesignCAD, with the Layer Toolbox and the Layer Options dialog. You can also manipulate layer properties with macros.


The Layer Toolbox

This is one of the tool boxes that normally appear at the top of the screen IF "Layer Toolbox" is enabled in the "View/Show-Hide" dialog or the "Options/Options/View" dialog (they are the same). The toolbox contains several unique and powerful tools to manipulate layers. For some things the Layer Toolbox is faster and easier to use than the Layer Options dialog, but it is not nearly as comprehensive.

A pull down layers list shows about a dozen layers. It has columns similar to the Layer Options dialog (described below) with the same functions. You can change the current layer by clicking on a layer in the list.

A Layer List Options tool displays a list of options to control the layers display.

The Same Layer As "finger" tool allows you to click on a selectable object (see the Selecting Objects post) in the drawing and change the current layer to the layer that object is on. This does not move selected objects to the new layer, it just changes the current layer.

The Apply Layer To Selection "A+" tool causes any selected objects to be moved to the current layer. This is much faster than opening the Info Box. Very useful!

The Enable/Disable Multi-Layer Editing tool enables or blocks selecting objects on any layer other than the current layer.

Consult the Reference Manual for descriptions of the other less used tools.


The Layer Options Dialog

Later versions of DesignCAD have two Layer dialogs. The newer "Layer Options" dialog is opened by pressing the "L" key. The old "Layer" dialog is opened with "Options/Options/Layer." Both have many common features, but the newer Layer Options dialog is much more versatile and user configurable - you can change the height and width of the dialog box to allow more layers and longer layer names to be visible, and you can change the order of the columns and enable/disable columns (see below). I will describe the new dialog, but many of the features are the same as in the old dialog.

Layer Index. Every layer has a number - this is shown in the "Index" column. This number is the current position of the layer in the list.

The index is not assigned to a specific layer (it is the position in the list), but layers are assigned to the index. So if you move a layer up/down in the list (see below) it assumes the new index position it occupies in the list. It is important to remember this if you use macro code that refers to an object by the layer index number. Remember, this number is not permanently linked to the objects in any specific layer, and if you shuffle the layer order the layer index for a specific object may change.

Current Layer. This is the layer where new objects will be drawn. All drawing occurs in the current layer.  The current layer is always visible (you cannot hide it) and editable (you cannot lock it).

The current layer is indicated by a colored pencil icon in the current Layer column that has a pencil icon in the header row. To change the current layer to another layer just left click in the Current Layer column in the box for the desired layer row. The pencil icon will move to the selected layer to show it as the new current layer where new objects will be drawn.

Layer Visibility.  You toggle visibility on/off by clicking on the light bulb icon in a layer row. Use this to turn off unneeded layers to reduce clutter and speed up window redraws.

When you print a drawing or save an image file only the visible layers will be used.

Layer Editability. One column contains lock icons. If a layer is not editable the icon appears locked. If it appears unlocked the layer is editable. Most users call this "locked" and "unlocked."

Only objects that are on visible and unlocked layers can be selected and edited (objects that can be selected are called "editable").

Objects on the current layer are always editable (visible and unlocked) - you cannot lock the current layer.

Other visible layers can be locked by clicking the lock icon to lock the layer. This allows you to see the objects on the layer, and gravity snap to them. But they will not be selected and you cannot edit them. This is useful for locking layers so you won't accidentally change the objects in these layers.

When you make a layer invisible it is automatically locked. When you make the layer visible again it will return to the locked or unlocked state it had before you made it invisible.

In the latest versions of DesignCAD when a file is opened the visible and invisible states that the layers had when the file was last saved will be restored. This has been somewhat unpredictable in some earlier versions.

You can lock all but the current layer with the "Lock All" button at the lower left of the dialog box. This locks all visible layers except the current layer, and all invisible layers are locked.

The "Unlock All" button unlocks all layers, including hidden layers. These unlocked hidden layers are not editable because the objects are invisible and cannot be selected. However, there is one exception to this rule. If a group or solid contains elements on multiple layers and one or more of these layers are locked, you cannot select the group or solid even though part of it is on a visible unlocked layer. "Unlock All" unlocks the hidden layers, allowing the group or solid to be selected. You can then perform limited operations on the group or solid such as change layers, colors or materials with the Info Box, explode the group or solid, or delete it.

Layer Occupied. One column in the layers list has an asterisk (*) in the header. This is the "occupied" column. Any layer that is not empty will have an asterisk in the box in this column.

There is a catch to this. If  the "Options/Options/General" option "Don't use nested groups" is not selected, when you create a group or nested group (see group discussion post) an invisible "group container" is created on the current layer, even if no part of the group or nested group is in that layer. If the layer contains no other objects it will appear empty when you view it, but it will have an asterisk in the occupied column in the Layer Options dialog. This can be very confusing. To avoid this enable the "Don't use nested groups" option. With this enabled empty layers will not be marked occupied.

Layer Name. You can give each layer a name by clicking on the box in the "Name" column and typing in the layer name. Finish by pressing Enter or clicking in another box in the table. Layer names are very useful in drawings with many layers.

You can drag the right side of the Layer Options dialog to the right to make the layer Name column wider. This allows entering long layer names. However, the Info Box and Layer Toolbox have much narrower layer name boxes so all of a long layer name will not be visible in these boxes (however, if you hover the cursor over the layer name box the full layer name will appear as a "tool tip" box).

Layer Properties. In some types of drawings, such as topographic maps, each layer is used to hold a single type of drawing element. You can have minor contour lines on one layer, major contour lines on another, streams or water features on another, vegetation on another, paved, gravel and dirt roads on separate layers, a layer for property boundaries, another for geographic coordinates, etc. Typically each of these features has a line color and a line style.

You can assign a color and line style to each layer, or you can just leave them unassigned, depending upon what you are drawing (the default is no assigned layer styles). In come cases, such as a topographic map, these assigned layer properties can make drawing much easier. But they don't make much sense for most 3D drawings. However, layer colors will allow you to determine which layer an object is on just by looking at it.

If a layer has assigned color or line style these properties override any other assigned property of objects in the layer. Normally when you make a layer current its color and line style (if any) become the drawing default, and whatever you draw will have that color or line style.

However, when you move an object from one layer to another that has assigned layer properties the assigned properties of the object do not change, but the display of the object will. So if you create an object on a layer with an assigned color of red, the base color of the object will be set to red. Then if you move that object to a layer that has an assigned green color the object will display green. But if you select the object and examine it in the Info Box it will still have a red base color. If you then move the object to a layer with no assigned color the object will again display red.

This may sound complicated, but if you think about it, it really is pretty simple. So far. BUT WAIT! You haven't seen anything yet!

If you select an object and open the Info Box  (CRTL I) you will see that near the bottom is a "Color by Layer" option, and lines have a "Line Style by Layer" option. If an object is created on a layer that has an assigned color or line style these options will be enabled. This is what caused the object to adopt the color and line style of the layer it is on (if any have been assigned). If no color or line style have been assigned to a layer the object displays with it's base color and line style.

But if the object is created on a layer that has no assigned properties these options will be disabled. When these objects are moved to a layer that has an assigned color or line style they will be displayed in their base color and line style and not the color and line style of the layer. If you want them to adopt the color or line style of the layers they are moved to you must select the object, open the Info Box and enable the "Color by Layer" and/or "Line Style by Layer" options.

Unless it is an odd numbered Tuesday in a month containing the letter "r" in which case all bets are off! Actually, it is a bit complicated, but it all makes sense and it gives you tremendous control over how layers affect the display of objects.

But for most drawings you probably will not use the layer properties. In this case you can disable the "Color" and "LineStyle" columns in the Layer options dialog.

Changing The Layer List. You can change the position of a layer in the list by left clicking somewhere in the layer row and using the up and down buttons on the right side of the Layer Options dialog. This causes the layer's Index number to change as it moves up/down to reflect the position of the layer in the list.

To enable or disable specific columns in the Layers dialog click on the title row at the top of the layers list. Select the "Show/hide column" item in the list, and another pop up list will show the options. You can also rearrange the order of the columns by clicking on the column header and using the "Move column left" or "Move column right" options.

At the bottom right of the layers dialog is a "Filter" pull down list showing several options. These control which drawing layers will be shown in the layers list. "All Layers" is the default. For example, if you select the "Named Layers Only" option only layers to which you have assigned a name in the "Name" column will be shown. The "Active or Named Layers Only" option shows all layers that have a name or are occupied (active) and all empty and unnamed layers will not be displayed.

The "Sort Layers by" function allows you to change the way the layers list is displayed. The default is to sort by the "Index" number. You can also sort alphabetically by layer "Name," by "Content" (occupied layers at the top of the list) and by "Status." "Status" changes the order so the current layer is at the top, followed by all visible and unlocked layers (occupied or not), with all locked layers (occupied or not) at the end of the list.

Enable multi-layer editing. This important option makes it possible for you to select objects on layers other than the current layer. It is enabled by default. If you disable this option you will be able to select only objects on the current layer. This is more or less the same as "Lock All" except if you change the current layers the previously current layer will be locked automatically.

There are a bunch of other options in the Layer Options dialog. Some are shown at the bottom of the screen. If you right click anywhere in the layers a list a long pop up menu of options will appear. Consult the Reference Manual for explanations of the less often used features.

Phil

« Last Edit: October 23, 2015, 03:00:55 PM by Dr PR »

Logged
DesignCAD user since 1987


January 31, 2015, 03:31:31 AM
#8
Phil.
I'm in awe of your willingness to take on this massive topic :)
Please refer replies #44 and $45 here  (maybe they give you or others some ideas) :-
http://forum.designcadcommunity.com/index.php?topic=5414.msg36652#msg36652
(edit)  The rest of this post is deleted because according to Phil, it qualifies as ... censored.  PS I thought I was being constructive ?? 


« Last Edit: February 01, 2015, 12:26:51 AM by samdavo »

Logged


January 31, 2015, 05:20:38 PM
#9
Cursor Movement and Setting Points

Cursor Movement

Nearly everything happens at the cursor position, so you need to be able to move it around with speed and accuracy. Of course you move the cursor with the mouse or trackball. But you can also move the cursor with the "Arrow" keys on the keyboard. "Left" and "Right" move the cursor horizontally along the X axis. "Up" and "Down" move the cursor vertically along the Y axis.

In 3D drawings the "Home" and "End" keys in combination with the "Crtl" key move the cursor along the Z axis deeper into the drawing (Ctrl Home) or closer to the screen (Ctrl End). Caution: The Home and End keys will move the cursor if the Ctrl key is not pressed, but it moves diagonally up or down to the left only.

If you hold down the "Shift" key while using the cursor movement keys the cursor will move with a different step size. You define the cursor steps in the "Options/Options/Cursor" dialog (or press the "I" key to open the dialog). The "Large Step Size" is the distance the cursor will move with the unshifted keys. The "Small Step Size" is the distance the shifted cursor keys will move the cursor.

Note: These names are misleading. The "Small Step Size" can be larger than the "Large Step Size."

There is one other curious historical option in the "Cursor" dialog. You can choose "Relative to Screen" or "Relative to Drawing" in the Step Size box. These represent two entirely different philosophies of just what you are creating - pictures on the screen or virtual objects in computer memory.

If "Relative to Screen" is selected the cursor always moves a certain number of pixels, regardless of how much you are zoomed in/out in the drawing. So if you zoom out to fill the screen with the entire drawing the cursor step will move relatively large drawing distances each time, and when zoomed way in the cursor step moves relatively short drawing distances. This is the way the original 2D Prodesign program worked in the mid 80s. The step movements had no relation to what you were drawing, and this was frustrating.

Later the "Relative to Drawing" option was introduced. In effect, each step size is defined in drawing units. Regardless of how much you are zoomed in or out the cursor always moves the same distance through the drawing. This is now the default mode.

Cursor Shape

The cursor normally is an arrow (the default). But when you start a command the cursor changes to a "+" in 2D or a representation of the three axes in 3D (a 3D X). You can change the shape of the cursor in the "Options/Options/Cursor" dialog. You have these choices:

3D cursor. This is a fixed size "+" in 2D, or the three dimensional "X" in 3D that changes size with the depth of the cursor in the drawing. It is larger closer to the screen and smaller farther away.

CrossHair. This is a huge "+" in 2D that crosses the entire window. In 3D it is a 3D "X" that spans the entire window.

Fixed Cursor. Only available in 3D, this is a fixed size 3D cursor. You can define the size in the "Fixed Cursor Size" box. The default value is 60.

****** CAUTION ****** CAUTION ****** CAUTION ****** CAUTION ****** CAUTION ****** CAUTION ******

It is tempting to set convenient cursor step sizes for the drawing you are making. For example, if you are working with 1.5 mm thick sheet metal or 0.625 inch thick circuit boards you could set cursor step sizes for these common dimensions. Then when you are drawing if you want to step these material thickness you could just press the cursor keys.

However, the cursor does not always stay where you put it. The mouse tail (cord) may get caught under something and pull the mouse after you take your hand off of it. Or, when you stop moving the cursor it may be right at the point between a "bit flip" where the least bit of the digital number the mouse is sending to the computer is at the verge of changing between 0 and 1. Any slight vibration can cause this bit to change and move the cursor slightly. Just typing on the keyboard or the vibration of a truck passing by can cause this.

I have seen it happen many times. And when it does, if you start drawing from the cursor position with the arrow keys or other cursor movement commands you will introduce a slight error into the drawing. These errors accumulate over time. I first discovered this in a drawing I had been working on for several days when I realized that almost all dimensions were off by a tiny bit. I had to scrap the drawing and start over.

Every mouse or trackball is susceptible to this error. YOU HAVE BEEN WARNED!

The point setting commands described below will allow you to draw without these errors creeping in - if you use them correctly.

******************************************************************************************



Placing Points

Almost all drawing functions are based upon setting points. DesignCAD has a collection of point setting functions that allow you to set points precisely at the desired positions. They are the key to accurate drawings, so learn to use them.

Point Relative. This is probably the most useful function of all. It allows you to set a new point an exact distance from an existing point. Start the function with "Point/Point Relative" or just press the shortcut single quote (') key.

At the right of the Point Relative dialog are three boxes where you enter the offsets (differentials) for DX, DY and DZ to define how far the program should set a point from a selected position. These distances will be in whatever drawing units you are using (if any).

On the left side of the dialog are three "Relative to" options for the selected position:

Last Cursor Position. The selected position is wherever the cursor is. This is the default option if no other points have been set - don't use it. It is susceptible to the cursor creep problem described above. If the cursor moves between the last time you moved it and when you finish the Point Relative command, the new point will be relative to wherever the cursor wandered off to!

Origin. This will set the new point relative to the drawing origin. The origin is a point where X=0, Y=0 and Z = 0. You can set the origin with the "Point/Origin" command. This option is not susceptible to cursor creep.

Reference Point. This allows you to set a new point relative to any selected reference position in the drawing. It is not susceptible to cursor creep. This is the most versatile option, but it requires you to set the reference point after you exit the Point Relative dialog. You can gravity snap to any existing point and the new point will be set relative to that point (if you just left click the new point will be relative to where the cursor is when you left click).

Last Point. If you have already set some points this will place the new point relative to the last point you set. It is not susceptible to cursor creep.

At the bottom of the Point Relative dialog are two more options:

Move cursor without setting point does just that. This is the same as pressing the gravity snap "Comma" key (,).

Always reset values to zero.  If the option is selected all values will be set to zero when the dialog opens again. If this is not selected the program remembers the last XYZ offsets that you used and places them in the offset boxes when the dialog opens again.

Note: Some other commands use the same options found in the Point relative dialog.

Point XYZ. This command sets a point at the exact XYZ position entered into the X, Y and Z boxes. Start the command with the "Point/Point XYZ" menu item or press the "Colon" key (:). This function is the same as the Point Relative command with the relative to origin option.

Point Polar. This allows you to set a point a defined distance and angle relative to some position in the drawing. Start the command with the "Point/Point Polar" menu or press the "Semicolon" key (;).

Enter the distance and angle in the boxes. Then select the drawing plane (XY, YZ or XZ) to determine the direction. You have the same "Relative to" options as the Point Relative function.

But what are the angles referenced to? Where is zero? This depends upon options in the  "Options/Options/General" dialog. You have two choices:

Mathematical. Zero degrees is the positive X axis and degrees increase counterclockwise. This is the default setting.

Geographical. Zero degrees is the positive Y axis (north) and angles increase clockwise.


****

Special Point Snap Functions

The program has some very useful predefined ways to set points that would be very difficult to set up using geometric constructions. You can enable some of these to appear automatically by turning on Running Snaps (see the "Commands or Functions" post).

These functions will snap (move) the cursor. If they are used inside other drawing functions (while drawing a line, for example) they will also set a point.

Line Snap. This moves the cursor to a point on the nearest line (or plane edge). Press the "K" key or use the "Point/Line Snap" menu or click the "L+" button in the Snap Toolbox.

This function calculates the shortest distance from the cursor position perpendicular to the nearest line and snaps the cursor to the line.

It is very similar to the "Draw/Line/Perpendicular to a Line" function except the Line Snap function doesn't draw a line, it just moves the cursor and possibly sets a point.

Plane Snap. This works exactly like Line Snap except it finds the perpendicular from the cursor to the nearest plane and moves the cursor to that point on the plane. Press the "F7" key, use the "Point /Plane Snap" menu, or click the Snap Toolbox icon (a square with a "+" in it).

If you start the Line (V) function, set a point, and then use Plane Snap it will draw a line perpendicular to the plane.

There is one caveat with this function - it will also snap perpendicular to the edges of planes. If you are trying to create a line perpendicular to the surface of the plane you must be certain that the cursor position is somewhere over the plane within the bounds of the plane. Otherwise the line will just be perpendicular to an edge of the plane and at a non-perpendicular angle to the surface.

Line Plane. This function sets a point at the intersection of a line and a plane. The line does not actually have to intersect the plane, and it can even be off to the side a bit and the function will still work. Use the "Point/Line Plane" menu or the Snap toolbox button (a square with a "+" and "\" in it). This function is so useful that I have assigned it to the hot key combination "Alt L".

Left click on the line and then move the cursor toward the desired plane. A small square will appear if the program finds the intersection. Left click to set the point when the point marker appears.

Note: If you try to find the intersection of a line and a curved grid you may get multiple solutions. As you move the cursor near the grid the selection point may jump around spastically as you are shown the intersection of the line with the geometrical plane of multiple grid facets.

Midpoint. This function finds the geometric midpoint in a line segment and moves the cursor there. Move the cursor near the line segment and use the "Point/Midpoint" menu, press Ctrl K of click the Snap Toolbox icon with "M+" in it.

One caveat with this is that some straight lines can actually have two segments, but they appear as a single segment. Midpoint will snap to the middle of one of the segments, and not the middle of the entire straight part of the line. Use Point Select mode (see the "Selecting Objects" post) to see how many points exist in the straight line, and remove a point if necessary.

Intersect 1 and Intersect 2. These functions find the intersections of a line with other lines, curves, circles, etc. They are essential for geometric constructions.

Note: These functions only find intersections of lines that lie in the same plane - they don't find near misses!

For Intersect 1 left click on a line. If it intersects with another line the cursor will move to the intersection point.

With Intersect 2 you click on a line (circle, curve, etc.) and move the cursor toward the other object. If they intersect a small square point marker will appear. Left click to move the cursor to the intersection point.

A caveat with these functions is that there may be many potential intersections. This is especially true if you are trying to find an intersection with something like a segmented circle that has several segments close to the line. As you move the cursor close to the circle many different intersections may flicker on and off. This can make it extremely difficult to select the desired intersection.

Tangent Snap. This function finds a point on a line from the cursor position tangent to a circle. Set a point and then move the cursor near a circle. A small square point marker will show the tangent point (there will be two, one on each side of the circle). Left click to snap to the tangent point. To execute the function use the "Point/Tangent Snap" menu or click the Snap toolbox icon with an arc and a line in it.

This is identical to the "Line Tangent To A Circle" function (Draw/Lines/Tangent to a Circle).

****

There are many more point setting and line drawing functions, but these are some of the more commonly used commands. Consult the Reference Manual for a full list of commands.

Phil
« Last Edit: February 16, 2017, 10:16:55 PM by Dr PR »

Logged
DesignCAD user since 1987


February 01, 2015, 06:33:40 PM
#10
Object Types Part 1

The things that we draw are called "entities" or objects. There are several basic types and there are some subtle differences between them that often cause confusion and problems for novices and experienced users alike. I'll try to explain these differences.

You can see a list of entity types that exist in a drawing by selecting the "Help/Drawing Info" menu item. The dialog tells the drawing size and the  number of layers in use, the number of points in the drawing and the number of entities. Below this is an "Entity Description" box with a detailed breakdown of entity types.

You can view the points used to define an entity by switching to Point Select Mode ("Ctrl 1" - see the Selecting Objects  post) and selecting the object. The points will be marked with small squares.

When an object is selected you can make a variety of changes with the menu options under "Edit/Selection Edit/ ..." or with the Info Box (see the "Changing Object Properties" discussion).

Simple Objects

Lines, Curves, etc.

The simplest entities are just a series of points connected by straight Lines or Curves. The spans between points are segments of the whole line or curve. You can move, add and delete points in Point Select mode. You can also move points in the Info Box, change line lengths, and such. These can be either 2D or 3D entities.

When creating Lines (the "V" key) and Curves (the "C" key) you can set a series of points that loop back on themselves with the last point at the same position as the first. This creates a closed polygon (Line) or loop (Curve). These are open figures with no "filling" in the middle. In 3D mode they always display just as lines or curves.

You can convert a closed segmented Line into a Plane (see below) with the "Edit/Selection Edit/Convert/Make Plane" function IFF all points of the Line lie in a geometrical two dimensional plane. The new Plane will have a color and material "filling." The currently assigned color in the Color Toolbox will be used and the current material (usually the "Default" material) will be used.

Actually, the command is pretty forgiving, and if a point isn't too far out of the same plane as the other points a dialog opens asking if you would like for the program to flatten all of the points into the same plane and then create a Plane entity. This function is so useful that I have created a custom Toolbox button for it so I don't have to work my way down through four levels of menus.

The "Draw/Lines/..." menu lists several options for creating Lines and Curves. Lines can also have width and patterns, and can be double lines. Read the Reference Manual for details of all these options.

Circles, ellipses, etc.

These objects are basic 2D entities that are defined by a mathematical formula. They can be used in either 2D or 3D mode. You can make some changes, like changing the radius of a circle or the position of the center point with the Info Box or moving the radius point in Point Select mode, but you cannot add or delete points. If you make more drastic changes, such as "Edit/Selection Edit/Convert/Vector Convert" the object will not longer be the same type and will no longer be defined by the mathematical formula.

These objects do not have any "filling" and display in 3D as simple curved lines.

Planes

Planes are actually filled geometrical polygons, and they are used in both 2D and 3D drawings. However, they do not display the same in 2D as they do in 3D. In 2D mode a Plane looks the same as a segmented Line of the same number of sides and dimensions.

But Planes include a "filling" that has color and material properties. In 3D wireframe planes look just like closed multi-segment lines, but in shaded 3D views they display as colored surfaces, with a color or material texture filling in the space between the edges. In contrast, segmented Lines display as open segmented lines in shaded 3D views, and they have no material properties.

The "Draw/Planes/..." menu lists several options for creating Planes.

When you work in 3D it is extremely important to understand the difference between an open polygon or loop drawn with Lines or Curves, and a filled Plane.

This difference causes a lot of confusion for new DesignCAD users - and occasionally for the more experienced users. Because they appear the same in 3D Wireframe mode it is easy to assume they are the same. But you cannot use Lines to create true solids (see below).

People often start with a 2D line drawing, like the floor plan of a house, and then attempt to Extrude ("Draw/Extrude" or the "X" key) the Lines to create walls and such. Then, because their extrusions look like solids in Wireframe view they assume they are solids and try to use the solid editing functions with them. These commands don't work with Line extrusions (see Grids below), leaving the users scratching their heads wondering what is wrong.

Only Planes or Grids will extrude to create true solids. In effect, the material "filling" of a Plane also extrudes to create the solid interior. If you extrude a closed Line polygon there is no "filling" and the result is a hollow Grid with open ends.

Grids

Grids are something else! They are 3D only objects that display as a surface or "quilt" of polygons, but they are actually another type of mathematical formula object. They can be perfectly flat, but most often are curved in three dimensions and look like a fishnet in Wireframe view. Grids are made up of rows and columns of identical rectangular elements often referred to as "facets." The formula defines the number of rows and columns, and includes a series of defining points.

Grids have a base color and a material, like Planes. Each facet is the equivalent of a Plane, and facets have a color and material "filling" like Planes. However it is a 2D "filling" limited to the zero thickness geometrical plane of the facet.

In Wireframe mode if you extrude (Draw/Extrude) a single Line segment you get a single facet Grid that looks like a Plane but isn't. If you extrude a multisegment Line you get a multifaceted single row Grid. If you extrude a closed (loop) multisegment line you get a closed single row multifaceted Grid that looks like a Solid, but isn't - the ends will actually be open and the grid forms a hollow tube.

It is this visual similarity between Grids and Solids that leads to confusion when you try to use the wrong tools (commands) with Grids.

Grids can be broken up into individual planes with the "Edit/Selection Edit/Convert/Explode function.

DesignCAD has two tools for creating complex Grids or "surfaces," the "Draw/Surface Patch" and "Draw/Surface Connect" commands. You can use these functions to create curved or wavy irregular surfaces. These are pretty complex functions that can create multirow grids that look like fishnets in Wireframe mode and curved surfaces in shaded views. See the Reference Manual for details, and search the Forum for posts giving tricks to use with these functions.

The points of the Grid can be moved in Point Select mode, but you can't add or delete points. CAUTION: If you move the points of a Grid you may create an object that cannot display properly in 3D shading. The reasons are too complex to explain here, but there are several threads on the Forum that go into great detail.

Solids

Solids are the basic drawing elements for 3D drawings. They represent real world solid objects in the CAD virtual 3D world. The Solid entity type is the most common (traditional) way DesignCAD represents solid objects.

Proper Solids. A "true" or proper solid is completely enclosed and has no inside surfaces or "leaks" between the inside and outside. The solid drawing functions (Box, Cylinder, etc.) always create proper solids. Only true solids can be used for 3D printing.

Improper Solids. An improper solid is not completely enclosed and has openings (leaks) between the inside and outside. It may have interior surfaces or multiple overlapping surfaces. With many drawing functions improper solids work just as well as true solids, but they cause problems with other functions. They may display in shaded images with openings to the inside.

DesignCAD uses grids to form parts of some proper solids. For example, if you use the Box tool ("Solids/Box" or the "]" key) to create a solid, and the use "Solids/Solid Explode" to break up the solid into it's component parts, you will find that there is a rectangular Plane on the bottom, a four-sided single row grid for the sides, and another rectangular Plane on the top. So the Box solid is actually a grid with the ends capped with Planes.

There are two fundamental ways to create 3D solids, Additive and Subtractive (see the "2D and 3D" post for details). Subtractive always creates proper solids. But DesignCAD allows you to select an object or collection of objects and define them to be a solid with "Solids/Solid Define." This is how improper solids are created - often accidentally without the user being aware of it. Improper solids often come back to haunt you - I speak from experience!

The "Solids\..." menu has a collection of tools to create basic solid shapes like boxes, cylinders, cones, spheres, tube, walls, etc. These are often good starting points for the creation of more complex solids.

You can also sweep a Plane around an axis to create a proper solid. If you sweep a closed segmented Line you get a closed Grid that just looks like a Solid - use "Solid Define" to make it a true solid. Often this creates an object with internal planes or flat planar ends that are divided into a bunch of segments. Here is a trick to clean up those interior surfaces and ugly ends:

1. Draw another simple proper solid like a box or cylinder that is off to the side of the first solid, and does not overlap (no common volume) the first solid.

2. Use "Solid Subtract" (see below) to subtract the second solid from the first. There isn't any common volume to subtract, but this causes DesignCAD to examine the first solid closely, and it will reduce the number of facets in the segmented ends into a single multisided Plane. This trick will often clean up multiple coincident sides and internal planes in improper solids.

The "Solids" menu has several "Boolean" solid tools to add two solids together (Solid Add), subtract one solid from another (Solid Subtract), find the common volume between two solids (Solid Intersect),  subtract the common volume between two solids (Exclusive Or), etc.

The "Solids/Solid Explode" function will break up a solid into individual components. However, if you originally selected a bunch of objects that included other true solids and grids and created a new solid with "Solid Define," when you explode this new solid the original solids will still be solids, and grids will still be grids. Multisegment lines will still be individual objects. So you can effectively nest solids inside other solids. Some people use the "Solid Define" function just to create another type of group (see below).

Individual solids can be broken up into their parts with the "Solid Explode" function.

Solid Surfaces

This is a new entity type for defining solid objects. It offers some advantages over the traditional solid entity type. It was introduced in Version 24 in November 2014 so I do not have much experience with this entity type.

Solid entities and Solid Surface entities look exactly alike. If you select a solid surface object and open the Info Box it will say the entity is a "solid surface." I think Solid Surface objects are always "proper" - they cannot have leaks between the interior and exterior.

The main difference between Solid Surfaces and traditional solids is that Grids are not used to create Solid Surfaces. Grids are a compact mathematical formula way to represent a surface, but they must be a uniform array of facets. If you use a solid that has a grid surface with the solid Boolean functions the Grid will be broken up into a large number of rectangles, and some facets may be converted to triangles. The number of individual objects increases greatly, increasing file size. In addition, some of the facets may be moved to other layers and the material may be changed.

Solid Surfaces were designed to be cut or perforated so they should behave much better with the solid Boolean operations.

You cannot create a Solid Surface object directly. You must create a traditional solid and then convert it to a Solid Surface object.

You can convert traditional "solids" to "solid surfaces" by selecting the object and using "Edit/Selection Edit/Convert/Solid To Surface."

You can convert "solid surfaces" to traditional "solids" by selecting the object and using "Edit/Selection Edit/Convert/Surface To Solid."

Solid Surfaces will be created by the solid Boolean functions ("Solid Add, "Solid Subtract," etc.) if the "Options/Options/General" option "Use surface representation for solid operations" is enabled. This normally defaults to off.

When this option is enabled the solid Boolean functions will combine two existing solids to create one new solid. If one or both of the original objects are traditional solids they will be combined into a Solid Surface entity.

If the "use surface representation" option is disabled you may still get a Solid Surface result. If both original solids are traditional solids the result will be a traditional solid. But if either of the original objects is a Solid Surface object the result will be a Solid Surface object.

OK, "So what? you may be thinking. Why should I use Solid Surfaces? The best reason is that Solid Surfaces can be exported to other programs with better results than with traditional solids. This will be especially important when 3D stereolithic file (STL) import/export is added to DesignCAD (scheduled for V25). This will allow DesignCAD STL file output to drive 3D printers directly. With older versions you must export files in DXF format and use another program to translate them into STL files. Unfortunately, traditional solids do not always behave well when they are exported the the resulting files must be edited and cleaned up before they can be used for 3D printing.

Another more philosophical reason for using Solid Surface entities is that they are "better" than the old solid entity. Since this would be getting into a discussion of what "better" means I'll leave it for other threads on the Forum.

When I learn more about this new entity type I will add to this section.

Phil
« Last Edit: October 23, 2015, 03:43:11 PM by Dr PR »

Logged
DesignCAD user since 1987


February 01, 2015, 06:37:18 PM
#11
Object Types Part 2

Compound Objects

These objects are made up of two or more simple objects lumped together in one of several ways. In a way traditional solids are compound objects since they may be composed of multiple planes and grids lumped together as a single object.

Compound objects are very similar in this respect. They are collections of simple and/or other compound objects into larger collections. These collections are treated (more or less) like single objects. That is the purpose of lumping them together in the first place.

Groups

Groups come in two types, simple and nested. Simple groups may or may not behave exactly like single objects. Unfortunately, nested groups do not, although they should (in my opinion - not everyone agrees on this point). If you are familiar with the way groups work in other programs - especially nested groups - you may find DesignCAD groups frustrating.

The "Options/Options/General" dialog has a "Don't use nested groups" option. This option affects both simple unnested groups and nested groups.

If "Don't use nested groups" is disabled you cannot use the Info Box to change the layers of the drawing entities in a group or nested group. Instead all that is moved is an invisible group container. Furthermore, when you create a group from drawing entities, no matter what layers they are on, the invisible drawing entity will be placed on the current layer, even if no parts of the group are on that layer.

If nested groups are enabled, when you select a group or nested group and open the Info Box it displays only the layer number of the invisible container. The "Occupied layers only" option will list all layers with parts of the group in the drop down layers list.

If "Don't use nested groups" is enabled you cannot create nested groups. However, when you create a group the invisible container is not created, and all objects remain on their respective layers. If you use the Info Box to change the layer of the group, all parts of the group will be moved to the new layer (this does not have to be the current layer). If parts of a group are on multiple layers the Info Box layer box will say "multiple." The "Occupied layers only" option will list all layers with parts of the group in the drop down layers list.

If it is important to you to be able to select a group and move all parts of it to any other layer just as you would move a single object you must disable nested groups.

Simple Groups. Simple groups, or just "groups," are created by selecting one or more objects and using "Tools/Groups/Group Define" or the Main Toolbox "Group Define" tool (three interconnected boxes). Groups may include parts on multiple layers. If you select any one of the objects in the group the rest will be selected if all parts are on editable layers (see the "Layers" discussion).

Once a group is selected you can edit some of it's properties with the Info Box - such as changing the color or material, etc. If you delete the selected part of a group all parts are deleted. If you move any part of a group all parts move with it. If the elements of the group are on multiple layers and you use the Move command to move the group, all parts on all layers will move together, and the parts stay on their original layers. Ordinary simple groups behave exactly like single objects if nested groups are disabled.

You can use the "Apply Layer To Selection" tool (A+) in the Layers Toolbox to change a group's layer to the current layer. However, if you change the layer with the "A+" tool, all objects in the group will be moved to the current layer (including the invisible container if nested groups are enabled).

You can ungroup all of the elements with "Tools/Groups/Group Explode" or the Group Explode button in the Main Toolbox. Each individual part then is no longer a part of that group and moves, edits and deletes independently.

You can add objects to a simple group by selecting the new object and the group and using "Group Explode" followed immediately by the "Edit/Select Previous" (Shift P) to reselect all of the objects, and then use "Group Define."

Nested Groups. These are groups of groups. You can enable or disable nested groups (they are enabled by default) in the "Options/Options/General" dialog. To disable them select the "Don't use nested groups" option.

Nested groups behave mostly like single groups. They can have parts on multiple layers, the Move command moves all parts as a single object (on all layers), and can be deleted (all elements, including other groups that are parts of the nested group. The Info Box can be used to change some of their properties.

If you are familiar how nested groups work in other programs you are in for a surprise with DesignCAD nested Groups. They do not always behave like single objects or simple groups.

What's going on? Nested groups have an invisible "container" that binds the parts together. When you select a nested group you are really just selecting the container. When you try to move the nested group to a new layer with the Info Box only the invisible container changes to the new layer - all of the actual drawing objects stay in their original respective layers. Furthermore, if you move the container to an otherwise empty layer, the Layer Options and Layer Toolbox (see the "Layers" discussion) dialogs show the empty layer to be occupied. But if you disable all other layers than the "occupied" layer you can't see anything because there are no drawing elements on the layer! This can be very confusing!

But there is hope for nested groups if you want all the drawing elements (and the container) on a single layer. Change the active layer to the desired layer and use the "Apply Layer To Selection" tool (A+) in the Layers Toolbox. This will move all parts of the nested group to the current layer. So the "A+" tool works with nested groups like the Info Box layer change operation works with simple groups - everything ends up on a single layer.

You can partially explode nested groups with "Tools/Groups/Group Explode" or the "Group Explode" button in the Main Toolbox. Each iteration of this function removes the outermost or highest level container and leaves any lower level groups and nested groups intact. So you can "unwind" nested groups down to any level.

If you want to explode all levels groups in a nested groups, including any simple groups that are a part of the nested group, use the "Tools/Groups/Recursive Group Explode" menu item or the "Recursive Group Explode" button in the Main Toolbox. This breaks up all levels of nested and simple groups into the individual elements.

Blocks

Blocks are a special type of group - more like a virtual group. Blocks are a collection of entities that are grouped together and given a name. After this you can include multiple instances of a block in your drawing - something like copying groups. But the difference is that there really is only one copy of the block in the drawing, and all other instances in the drawing are just place holders that display like the collection of real objects in the block would display.

Blocks behave like single objects - or simple groups. All elements move together. The original block elements can include objects on multiple layers. This allows you to show/hide parts of a block by enabling or disabling the layers the original parts were on. You can select and delete a block placeholder.

Why would you want to use a block? One reason is to reduce the file size. Blocks were invented back in the days of limited RAM and small hard drives. Instead of multiple copies of objects - which inflate file size, only multiple block placeholders are included. That makes the file smaller. With modern computers having more RAM than we can use and huge hard drives, this reason for using blocks isn't as important as it was.

BUT - there is an even better reason for using blocks! You can edit the original instance of the block, and that changes all instances in the drawing. So if you have dozens of instances of the block in a drawing (say a tree in an architectural drawing) and you decide you want to change them all, you just need to edit the original block. Then all block place holders with that block name will display the changes.

Creating A Block. You use "Tools/Block Define" to create a block. First select the objects you want in the block and start the command. You enter a name, then select "Convert to block" in the options, and click "OK." This bundles all of the original parts into a block, much as "Group Define" puts all of the parts into a group. You also have an option "Retain" that creates a new block, but leaves the individual parts in the drawing. A third "Delete" option creates the block but deletes the individual elements that were used to create it from the drawing. This causes the elements to disappear, but when you insert a copy of the block the copy displays.

Inserting A Block. The "Tools/Block Insert" function inserts block placeholders into the drawing. These display just like copies of the original block elements. These placeholders behave like individual objects - because they are. You can also Copy/Paste blocks into the drawing or select and Duplicate (R) them. You can Copy or Duplicate any instance (placeholder) - you don't have to go back to the original copy.

The "Block Insert" function has several options. First select the block name from the "Name" list.

The Explode option inserts the individual parts into the drawing. They are no longer parts of a block and may be edited individually.

Select after insertion causes the block to be automatically selected after insertion into the drawing - handy if you want to move it after insertion.

Use Original Color causes the block elements to be the same color as the original. If this is not selected all elements of the block will assume the currently assigned color in the Color Toolbox.

You can also change the scale and rotation of the block when you insert it. Read the Reference Manual for details. If the original block had multiple handles (see the "Handles" discussion) you can use them to rotate the new block as you place it.

Exploding Blocks. You can explode an existing instance of a block with "Edit/Selection Edit/Explode." This replaces the block placeholder with individual elements of the original block. This is useful if you want another similar but different block. Place a copy of the first block, explode it, make the changes, and the select the parts and define them to be a new block with a different name.

So what if you insert a block into your drawing and then decide not to use it? It still hangs around as unused garbage, and clutters the block list when you are inserting other blocks. The "Tools/Purge Unused Blocks" function will remove all unused block definitions from a drawing file.

As usual, there are a few possible complications with blocks if you try to do exotic things with them. There are discussion elsewhere on the Forum of some of the more inventive things you can do with blocks.

Symbols

Last, but not least, are symbols. These are external files that you insert into another drawing. Each symbol is a separate file that you create with DesignCAD (or use the symbols supplied with DesignCAD). You have to tell DesignCAD where symbols are stored on your computer with the "Options/Options/File Locations" dialog.

Symbols work a lot like blocks - you insert  a placeholders into the drawing that displays as the drawing elements of the symbol file.

However, symbols are different in one VERY important way. The program does not save the elements of the symbol file with a drawing. It just saves a link to the symbol file. If you edit the original symbol file after it has been used in other drawings, this changes the symbol in ALL drawings that are linked to the symbol file. For example, say you use a symbol file containing a company logo in a drawing title block. If the company logo changes, or the company is bought by another company, all you need to do is edit the logo symbol file and that changes the title block logo in every file that uses the logo symbol file.

If you move the drawing file to a different computer without copying the symbol files as well, DesignCAD will not display anything for the symbols. The symbol files must be in the exact same folder location on the new computer as on the original computer.

Creating Symbol Files. You can draw anything and use it as a symbol in other drawings. The original symbol file MUST include Drawing Handles (see the "Handles" discussion). When you place a symbol into a new drawing you use these Drawing Handles to orient and scale the symbol. No handles, no Symbol! Use the "Point/Set Drawing Handles" function to set the handles for a drawing. Then use "File/Save as Symbol" function to save the file as a symbol file. Read the Reference Manual to see a selection of options for saving a symbol file.

Inserting Symbols. To insert a symbol into a drawing use the "File/Load Symbol" function. You orient the symbol in the drawing by positioning it's handles (see the "Handles" discussion). The symbol placeholder exists on the layer that you place it on, and the visibility of all elements in the symbol depends upon the visibility of the layer the placeholder is on.

There are many options for inserting symbols. You can explode them into the individual components in the new drawing (no link needed to the original symbol file). You can automatically group the elements of an exploded symbol. You can insert symbols as blocks (again, no link needed to the original symbol file). Symbols can be exploded with" Edit/Selection Edit/Convert" after they are incorporated into a drawing. You can have libraries of symbols. Read the reference Manual part on symbols to learn all the things you can do with symbols.

Phil
« Last Edit: April 23, 2015, 11:06:27 PM by Dr PR »

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DesignCAD user since 1987


December 11, 2019, 10:31:17 PM
#12
bump

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DesignCAD user since 1987


December 12, 2019, 10:57:19 AM
#13
Considering that all of this was written in 2015 several versions back, it is still all totally applicable to the latest version, and fortunately the developers have mostly resisted the urge to improve things at the expense of breaking, changing, moving or otherwise messing up existing things.

A few notable additions since that time are:

Insert manager - V2106 - allows you to inspect symbols and blocks used within a drawing

Block Editor - V2016 - allows you to edit in detail an existing block, the changes will appear in all instances of this block.  This could previously only be accomplished by recreating and redefining the block.

Custom properties - V2016 - allows you to assign custom properties to objects - not sure anyone has figured out what purpose this could serve and who would have wanted it.   Also beware - opening drawings with custom properties assigned in previous versions will lose data.

Autohatch  - V2018 - entities are hatched as they are drawn

Mixed mode rendering - V2018 - shows edges in shaded objects

Solids leak test - V2018

Pdf import - V2019 - this allows you to import surprisingly accurate geometry from 2D pdf files

RedSDK terminated - after many years of trying the effort to get REd SDK to work with designcad was abandoned - and the latest release of V2018 update no longer has it available.

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