First Steps CAD - documentation gCAD3D
Mainfunction CADInteractive creation and modification of objectcodes. Select the CAD checkbox. How to move, zoom, rotate the view How to operate CAD Create objects: Construct wireframe elements Construct surfaces Construct a CompositeCurve Cylinder/prism design Create assembly Load bitmap Activity Modify objects: Modify existing points Trim a line Mirror a line
Construct wireframe elements A slotted hole design: Select main module CAD; Select CAD feature “CIR Cen Radius"; Define the center point (left mouse button in the graphics window), key the radius, move to the next input field with the cursor-down button or the tab-button, (not return); Z-axis input vector (DZ is predefined); You will see the circle now; Modify: Esc key deletes the contents of the input field; Cursor-down key: new preview of the object. Save the object: Create the object with OK button, return-key or right mouse button "OK". You can inspect the object code (text) with function MAN. Create a second, adjacent circle. Produce tangents to the 2 circles: activate CAD-function "LN tangent"; Select the two circles, If necessary, select the next version with the PageDown-button, go back with picture-up-button; "2" provides second solution. Save object. Get intersectionpoint line circle: ( used later as startpoint / endpoint of contour) activate CAD-function Trim intersect / "INT (intersect)" select circle select line Save object (the intersection-point). Create a closed contour: activate CAD-function Curves / "S Contour" select the intersection-point, select all contour-objects in counterclowise order (or use the "REV" button) select the intersection-point (endpoint), Save object. Create surface from closed contour: activate CAD-function Surfaces / "A Planar Surf" select the contour Save object. File the model: activate File/save Model as/gcad key "Test1" button SAVE The model is saved as file Test1.gcad in the active output directory. You can view/modify this file with any text editor. Export as DXF File/save Model as/DXF ..
Constructing surfaces To construct a surface, the outer-contour is required. Inside the outer-contour can be internal-contours (holes). The contours must be closed. For contours can be used circle, ellipse, closed-polygon or closed CCV. Create the contours: create a circle create a second circle inside the first circle (a hole) Create the surface: Select CAD-function "A planar Surface" Select the outer contour and all inner contours. Save object (right mousebutton). VRML Export: Surfaces can be saved as a VRML file; File/save model as / VRML2 or VRML1
Constructing a CompositeCurve You can connect curves of different types to a contour. You do not have to trim the individual parts. The first and the last inputobject should be a point, internal points can be used. CAD-function "S Contour (CCV)" select the startpoint Select all contour elements remove an invalid selection: Use the delete button in the LineEdit window. turn direction (eg circle): select "CW" (in the LineEdit window) select the endpoint Save object (right mousebutton). See also CAD-CCV
Constructing a cylinder/prism For prisms (as for a surface) a closed contour is required. CAD-function "B Prism Base Thick" Select contour (eg S20); Enter thickness "50") or Enter Z-vector ("D(0 0 50)") or Define a point ("P(0 0 100)") - generates a cone Preview with cursor-down key Save object (right mousebutton).
Create an Assembly An assembly consists of loaded and positioned Sub-models. A sub-model can be placed by: - Origin [and an X-and Z-axis] or - Origin and a reference system (a plane (PLN, "R")) Clear model Space: File/New. Load / use external models (native models (.gcad), mockup models (.wrl .obj): CAD-function "M ext.Model Filename Pos' Input 'Filename': Push middle mouse button (in the graphics window), Select a model file, or - if the Model is already loaded - select model. Position (select the input field for 'Position' or the cursor-down key): indicate position in the graphics window with the left mouse button or key in, eg. "P(100 100 100)" Z-Axis (optional): Default is "DZ" (must be entered when an X-Axis is defined). All the text entries must be without apostrophes! X-axis (optional): Default is DX, "DY" rotates the model 90 degrees, "D(1 1 0)" (a reference vector) rotates by 45 degrees. Save object (right mousebutton). Load native Models into the active model: subModels / load Submodel from File Load the desired model (is created as an internal model, is not yet visible) Use internal Model: CAD / 'M int.Model' 'Sub-model': middle mouse button (in the grafic window) - select model .. Load STEP, IGES, DXF models as sub-models: Must currently first be loaded directly (File/Open Model), then be filed in native format (.gcad) can now be used as subModel ..
Load bitmap Bitmaps can be displayed simultaneously with 3D objects; Bitmaps are always shown normal to the view surface. Files with format .JPG and .BMP can be imported. Load Bitmap: Select CAD function 'N Image Pos Filename' 'point image': give the lower left position of the bitmap 'StartPoint Line' optional: if you want a line to the image: Select the start point of the reference line 'Linetype' optional: 1 = full, 2 = dashed, 3 = dash-dot 'Filename': use middle mouse button to select a bitmap-file 'Scale' optional: 0.2 gives Image reduced to 20% of original View with the cursor-down button. Save object with right mouse button. If no scale (or value 0) is defined, then the bitmap is dynamically scaled. Where there is a scale, this scale is fixed.
Activity Any CAD object can be linked to an interaction, eg: - move View position (to a predefined view position) - load a predefined model (such as HTM HREF) - run a supplementary program (DLL) Interaction is active in mode VWR, and inactive in modes CAD and MAN. (in CAD or MAN activate with Options/Interaction). Create Activity 'change view position': Select CAD-function 'Interact connect' 'connect object': select an object (selection of this object will activate the view-change) 'command': Now set the desired View position (zoom, pan ..) Now select Insert/viewport (from the top menu bar), - the View parameteris are written into the input field. Save object (right mousebutton). Test Activity: select main mode VWR and pick the object. Create Activity 'Load model': Select CAD-function 'Interact connect' 'connect object': select an object (selection of this object will activate the view-change) 'command': enter: LDMOD Data/sample_mod_blech1.gcad Save object (right mousebutton). This has generated the following code: I20 = N20 "LDMOD Data/sample_mod_blech1.gcad" (where N20 is the activating object, the model "Data/sample_mod_blech1.dat" is loaded with the selection of N20). Before the test, Save to File/save Model or Ctrl-S. Create Activity 'Start program': Enter 'command': EXECM DemoKondensatorplatte This will load the library DemoKondensatorplatte.so (.dll in MS-Win) and start the function gCad_main. For details, see .. /doc/gCAD3D_prog_de.txt. See also model sample_activ_1.dat
Create a tag with the text "Exit" Select CAD function 'N TAG type, line, text' 'Type + Color' Enter "23" (without quotation marks) to make a block of colour green; For details, see documentation 'TextPoint' defines the left middle of the text block 'Start Point', 'Line' and 'Linetype' remains' empty - no connecting line 'text' "Exit" (without quotation marks).
Modify existing points Finish the active CAD-function with the Esc-key. (several times if inputfields are not empty). Modify existing point: select point with right mousebutton, select function "move points". Move mouse, select new position (with left mousebutton), save with right mousebutton. Modify points of line or curve: select object with right mousebutton, select "move points". Select the point to move (yellow rectangle). Move mouse, select new position (with left mousebutton), Select next point to move or save with right mousebutton. For detailed info see PED_en.htm
Trim a line - create 2 crossing lines: select "LN PT PT", indicate 2 points, press right mousebutton. - create the intersectionpoint: select "INT(intersect)", select both lines, press right mousebutton. - trim line: select "CUT(trim)", select the line to trim, select the point, select alternate version if necessay: click into field "[solutionNr]", key PageDown (twice), press right mousebutton.
Mirror a line - create mirror-plane: select "PLN PT Z-Axis", indicate the position of the plane, define the Z-axis (eg select or key "DY"), press right mousebutton. - mirror line: select "Mirror obj", select the line, select the plane, press right mousebutton.
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