1 / 31

Bruce Mayer, PE Licensed Electrical & Mechanical Engineer BMayer@ChabotCollege

Engineering 22. Surface Modeling - 1. Bruce Mayer, PE Licensed Electrical & Mechanical Engineer BMayer@ChabotCollege.edu. Learning Goals. Use AutoCAD Built-In Commands to make “Primitive” 3D Surface-Shapes Box, Sphere, Cone, Pyramid, others Draw Surface of Revolution using a Shape & Axis

lei
Download Presentation

Bruce Mayer, PE Licensed Electrical & Mechanical Engineer BMayer@ChabotCollege

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Engineering 22 SurfaceModeling - 1 Bruce Mayer, PE Licensed Electrical & Mechanical EngineerBMayer@ChabotCollege.edu

  2. Learning Goals • Use AutoCAD Built-In Commands to make “Primitive” 3D Surface-Shapes • Box, Sphere, Cone, Pyramid, others • Draw Surface of Revolution using a Shape & Axis • Connect two Shapes with Straight Lines to Make “Ruled” Surfaces • Build Complex 3D Shapes by Adding & Subtracting Primitives

  3. Invoke Surface-Shapes SurfacesToolBar • Or Command Line • ai_XXX • XXX = box, wedge, pyramid, cone, etc.

  4. Draw Box • Pick Length & Width Using Ortho-Snap and Mouse • Specify Height from KeyBoard • “ENTER” To NOT Rotate Command: _ai_box Specify corner point of box: Specify length of box: Specify width of box or [Cube]: <Ortho off> Specify height of box: 7 Specify rotation angle of box about the Z axis or [Reference]:

  5. Add to End of Box • Pick Length Using Ortho-Snap and Mouse • Pick Width and Height using END Option to Pick Box Corners • “ENTER” To NOT Rotate Draw Wedge Command: ai_wedge Specify corner point of wedge: >> Specify corner point of wedge: end of Specify length of wedge: Specify width of wedge: end of Specify height of wedge: end of Specify rotation angle of wedge about the Z axis:

  6. Draw Rect-Base Pyramid • Enter Pts From KeyBd • Pyramid Apex OffCenter from base Command: ai_pyramid Specify first corner point for base of pyramid: Specify second corner point for base of pyramid: 11,0 Specify third corner point for base of pyramid: 11,7 Specify fourth corner point for base of pyramid or [Tetrahedron]: 0,7 Specify apex point of pyramid or [Ridge/Top]: 7,5,9

  7. Draw Triangle-Base Pyramid • Triangle Pyramid → a TETRAHEDRON • Enter Pts From KeyBd Command: _ai_pyramid Initializing... 3D Objects loaded. Specify first corner point for base of pyramid: 0,0 Specify second corner point for base of pyramid: 8,2 Specify third corner point for base of pyramid: 2,8 Specify fourth corner point for base of pyramid or [Tetrahedron]: t

  8. Draw Ridged Pyramid • Base & 2-Sides → Quadrilaterals • Ends → Triangles • Enter Pts From KeyBd Command: ai_pyramid Specify first corner point for base of pyramid: 0,0 Specify second corner point for base of pyramid: 10,0 Specify third corner point for base of pyramid: 10,10 Specify fourth corner point for base of pyramid or [Tetrahedron]: 0,10 Specify apex point of pyramid or [Ridge/Top]: R Specify first ridge end point of pyramid: 3,5,10 Specify second ridge end point of pyramid: 7,5,7

  9. Draw Truncated Cone • Enter Pts From KeyBd • Could Also make Full Cone by Setting Top-Radius to ZERO Command: _AI_CONE Specify center point for base of cone: 5,5 Specify radius for base of cone or [Diameter]: 6 Specify radius for top of cone or [Diameter] <0>: 3 Specify height of cone: 8.7 Enter number of segments for surface of cone <16>:

  10. Draw Dish • Enter Pts From KeyBd • This is a SEMIsphere; Could Also make • Full Sphere • HEMIsphere (dome) Command: _ai_dish Specify center point of dish: 5,5 Specify radius of dish or [Diameter]: 8.8 Enter number of longitudinal segments for surface of dish <16>: 17 Enter number of latitudinal segments for surface of dish <8>: 11

  11. Draw 3D Face • 3DFaces are flat surfaces with 3 or 4 straight edges. Command: _3dface Specify first point or [Invisible]: 0,0 Specify second point or [Invisible]: 10,0 Specify third point or [Invisible] <exit>: 10,10 Specify fourth point or [Invisible] <create three-sided face>: 0,10 Specify third point or [Invisible] <exit>: 0,10,5 Specify fourth point or [Invisible] <create three-sided face>: 10,10,5 Specify third point or [Invisible] <exit>: 10,15,5 Specify fourth point or [Invisible] <create three-sided face>: 0,15,5 Specify third point or [Invisible] <exit>:

  12. Revolved Surface • The REVSURF command creates a surface, based on the revolution of a curve about an axis. • The curve can be a line, spline, polyline, arc, circle, ellipse, or elliptical arc. • SURFTAB1 and SURFTAB2 system variables control the number of divisions in the final 3D mesh

  13. RevSurf Example • Make Bowl with a Nice Base by Revolving a Closed-Form About a Vertical Axis Axis of Revolution Form toRevolve

  14. Increase the WireFrame Density Set SHADING & SurfTab Command: surftab1 Enter new value for SURFTAB1 <6>: 36

  15. Turn into ONE Object Command: pedit Select polyline or [Multiple]: Object selected is not a polyline Do you want to turn it into one? <Y> y Enter an option [Close/Join/Width/Edit vertex/Fit/Spline/Decurve/Ltype gen/Undo]: j Select objects: 1 found Select objects: 1 found, 2 total Select objects: 1 found, 3 total Select objects: 1 found, 4 total Select objects: Specify opposite corner: 0 found Select objects: 1 found, 5 total Select objects: 1 found, 6 total Select objects: 1 found, 7 total Select objects: 1 found, 8 total Select objects: 1 found, 9 total Select objects: 1 found, 10 total Select objects: 1 found, 11 total Select objects: 1 found, 12 total Select objects: 1 found, 13 total Select objects: 1 found, 14 total Select objects: 1 found, 15 total Select objects: 14 segments added to polyline Enter an option [Open/Join/Width/Edit vertex/Fit/Spline/Decurve/Ltype gen/Undo]:

  16. Change to IsoMetric View

  17. Invoke RevSurf Select object to revolve: Select object that defines the axis of revolution: Specify start angle <0>: Specify included angle (+=ccw, -=cw) <360>: Object that defines the axis of Revolution Object to Revolve

  18. Increase SurfTab2 Resolution Command: surftab2 Enter new value for SURFTAB2 <6>: 12 Command: Command: Command: _revsurf Current wire frame density: SURFTAB1=36 SURFTAB2=12 Select object to revolve: Select object that defines the axis of revolution: Specify start angle <0>:

  19. SurfTab2 = 6 SurfTab2 = 12 SurfTab Comparison

  20. Tabulated & Ruled Surfaces • Set Up: • Shade Mode → Gouraud Shaded, Edges on • SurfTab1 Value → 8 Command: _shademode Current mode: Gouraud+Edges Enter option [2D wireframe/3D wireframe/Hidden/Flat/Gouraud/fLat+edges/gOuraud+edges] <Gouraud+Edges>: _o Command: _shademode Current mode: Gouraud+Edges Enter option [2D wireframe/3D wireframe/Hidden/Flat/Gouraud/fLat+edges/gOuraud+edges] <Gouraud+Edges>: _o Command: surftab1 Enter new value for SURFTAB1 <6>: 8

  21. Invoke TabSurf Object for Direction Vector Object forPath Curve Surface is Quite COARSE → Change Resolution Command: _tabsurf Current wire frame density: SURFTAB1=8 Select object for path curve: Select object for direction vector:

  22. Increase SurfTab1 Resolution Command: surftab1 Enter new value for SURFTAB1 <8>: 36 Command: _tabsurf Current wire frame density: SURFTAB1=36 Select object for path curve: Select object for direction vector: Looks Much Better

  23. RuleSurf on Ellipses

  24. Invoke RuleSurf Command: _rulesurf Current wire frame density: SURFTAB1=36 Select first defining curve: Select second defining curve: First Defining Curve SecondDefining Curve

  25. Game Plan Make Ø35 circle in WCS Move UCS to Ctr Move UCS up 10 New Circle Above previous Ruled Surface Between Circles Frustum of Cone on Top of Circle EX15-10 – Pedestal Cone Time For Live Demo

  26. All Done for Today DoNutsAnyone?

  27. Engr/Math/Physics 25 Appendix  Time For Live Demo Bruce Mayer, PE Licensed Electrical & Mechanical EngineerBMayer@ChabotCollege.edu

  28. Make Blue Obj Layer EX15-10.1 Command: snap Specify snap spacing or [ON/OFF/Aspect/Rotate/Style/Type] <10.0000>: 5 Command: '_layer Command: z*Cancel* Command: c CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: Specify radius of circle or [Diameter]: d Specify diameter of circle: 35

  29. Move UCS and Make 2nd circle Command: ucs Current ucs name: *WORLD* Enter an option [New/Move/orthoGraphic/Prev/Restore/Save/Del/Apply/?/World] <World>: m Specify new origin point or [Zdepth]<0,0,0>: Command: _-view Enter an option [?/Categorize/lAyer state/Orthographic/Delete/Restore/Save/Ucs/Window]: _swiso Regenerating model. Command: ucs Current ucs name: *NO NAME* Enter an option [New/Move/orthoGraphic/Prev/Restore/Save/Del/Apply/?/World] <World>: m Specify new origin point or [Zdepth]<0,0,0>: z Specify Zdepth<0>: 10 Command: c CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 0,0 Specify radius of circle or [Diameter] <17.5000>: d Specify diameter of circle <35.0000>: 35 EX15-10.2

  30. Improve SurfTab1 Make Ruled Surface Command: surftab1 Enter new value for SURFTAB1 <6>: 60 Command: Command: Command: _rulesurf Current wire frame density: SURFTAB1=60 Select first defining curve: Select second defining curve: Command: EX15-10.3 • Next

  31. Build Cone in 10-High UCS Make 60 segments to Match Base EX15-10.4 Command: _ai_cone Specify center point for base of cone: cen of Specify radius for base of cone or [Diameter]: d Specify diameter for base of cone: 35 Specify radius for top of cone or [Diameter] <0>: d Specify diameter for top of cone <0>: 20 Specify height of cone: 30 Enter number of segments for surface of cone <16>: 60

More Related