[email protected] ENGR-22_Lec-26_SurfaceModel-1.ppt 1 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Bruce Mayer, PE Licensed Electrical

[email protected] • ENGR-22_Lec-26_SurfaceModel-1.ppt1

Bruce Mayer, PE Engineering 22 – Engineering Design Graphics

Bruce Mayer, PELicensed Electrical & Mechanical Engineer

[email protected]

Engineering 22

SurfaceSurfaceModeling Modeling

- 1- 1



Learning GoalsLearning 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



Invoke Surface-ShapesInvoke Surface-Shapes

SurfacesToolBar

Or Command Line• ai_XXX

– XXX = box, wedge, pyramid, cone, etc.



Draw BoxDraw Box Pick Length & Width Using

Ortho-Snap and Mouse Specify Height from KeyBoard “ENTER” To NOT Rotate

Command: _ai_boxSpecify corner point of box:Specify length of box:Specify width of box or [Cube]: <Ortho off>Specify height of box: 7Specify rotation angle of box about the Z axis or [Reference]:



Draw WedgeDraw Wedge 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

Command: ai_wedgeSpecify corner point of wedge: >>Specify corner point of wedge: endofSpecify length of wedge:Specify width of wedge: endofSpecify height of wedge: endofSpecify rotation angle of wedge about the Z axis:



Draw Rect-Base PyramidDraw Rect-Base Pyramid Enter Pts From KeyBd Pyramid Apex

OffCenter from base

Command: ai_pyramidSpecify first corner point for base of pyramid:Specify second corner point for base of pyramid: 11,0Specify third corner point for base of pyramid: 11,7Specify fourth corner point for base of pyramid or [Tetrahedron]: 0,7Specify apex point of pyramid or [Ridge/Top]: 7,5,9



Draw Triangle-Base PyramidDraw Triangle-Base Pyramid

Triangle Pyramid → a TETRAHEDRON

Enter Pts From KeyBd

Command: _ai_pyramidInitializing... 3D Objects loaded.Specify first corner point for base of pyramid: 0,0Specify second corner point for base of pyramid: 8,2Specify third corner point for base of pyramid: 2,8Specify fourth corner point for base of pyramid or [Tetrahedron]: t



Draw Ridged PyramidDraw Ridged Pyramid Base & 2-Sides →

Quadrilaterals Ends → Triangles Enter Pts From KeyBd

Command: ai_pyramidSpecify first corner point for base of pyramid: 0,0Specify second corner point for base of pyramid: 10,0Specify third corner point for base of pyramid: 10,10Specify fourth corner point for base of pyramid or [Tetrahedron]: 0,10Specify apex point of pyramid or [Ridge/Top]: RSpecify first ridge end point of pyramid: 3,5,10Specify second ridge end point of pyramid: 7,5,7



Draw Truncated ConeDraw Truncated Cone

Enter Pts From KeyBd Could Also make Full Cone

by Setting Top-Radius to ZERO

Command: _AI_CONESpecify center point for base of cone: 5,5Specify radius for base of cone or [Diameter]: 6Specify radius for top of cone or [Diameter] <0>: 3Specify height of cone: 8.7Enter number of segments for surface of cone <16>:



Draw DishDraw Dish

Enter Pts From KeyBd This is a SEMIsphere;

Could Also make • Full Sphere

• HEMIsphere (dome)

Command: _ai_dishSpecify center point of dish: 5,5Specify radius of dish or [Diameter]: 8.8Enter number of longitudinal segments for surface of dish <16>: 17Enter number of latitudinal segments for surface of dish <8>: 11



Draw 3D FaceDraw 3D Face

3DFaces are flat surfaces with 3 or 4 straight edges.

Command: _3dface Specify first point or [Invisible]: 0,0Specify second point or [Invisible]: 10,0Specify third point or [Invisible] <exit>: 10,10Specify fourth point or [Invisible] <create three-sided face>: 0,10Specify third point or [Invisible] <exit>: 0,10,5Specify fourth point or [Invisible] <create three-sided face>: 10,10,5Specify third point or [Invisible] <exit>: 10,15,5Specify fourth point or [Invisible] <create three-sided face>: 0,15,5Specify third point or [Invisible] <exit>:



Revolved SurfaceRevolved 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



RevSurf ExampleRevSurf Example

Axis of Revolution

Form toRevolve

Make Bowl with a Nice Base by Revolving a Closed-Form About a Vertical Axis



Set SHADING & SurfTabSet SHADING & SurfTab Increase the

WireFrame Density

Command: surftab1

Enter new value for SURFTAB1 <6>: 36



Turn into ONE ObjectTurn into ONE ObjectCommand: peditSelect polyline or [Multiple]:Object selected is not a polylineDo you want to turn it into one? <Y> yEnter an option [Close/Join/Width/Edit vertex/Fit/Spline/Decurve/Ltype gen/Undo]: jSelect objects: 1 foundSelect objects: 1 found, 2 totalSelect objects: 1 found, 3 totalSelect objects: 1 found, 4 totalSelect objects: Specify opposite corner: 0 foundSelect objects: 1 found, 5 totalSelect objects: 1 found, 6 totalSelect objects: 1 found, 7 totalSelect objects: 1 found, 8 totalSelect objects: 1 found, 9 totalSelect objects: 1 found, 10 totalSelect objects: 1 found, 11 totalSelect objects: 1 found, 12 totalSelect objects: 1 found, 13 totalSelect objects: 1 found, 14 totalSelect objects: 1 found, 15 totalSelect objects:14 segments added to polylineEnter an option [Open/Join/Width/Edit vertex/Fit/Spline/Decurve/Ltype gen/Undo]:



Change to IsoMetric ViewChange to IsoMetric View



Invoke RevSurfInvoke RevSurfSelect object to revolve:Select object that defines the axis of revolution:Specify start angle <0>:Specify included angle (+=ccw, -=cw) <360>:

Object to Revolve

Object that defines the axis of Revolution



Increase SurfTab2 ResolutionIncrease SurfTab2 ResolutionCommand: surftab2Enter new value for SURFTAB2 <6>: 12Command:Command:Command: _revsurfCurrent wire frame density: SURFTAB1=36 SURFTAB2=12Select object to revolve:Select object that defines the axis of revolution:Specify start angle <0>:



SurfTab ComparisonSurfTab Comparison SurfTab2 = 6 SurfTab2 = 12



Tabulated & Ruled SurfacesTabulated & Ruled Surfaces Set Up:

• Shade Mode → Gouraud Shaded, Edges on

• SurfTab1 Value → 8Command: _shademode Current mode: Gouraud+EdgesEnter option [2D wireframe/3D wireframe/Hidden/Flat/Gouraud/fLat+edges/gOuraud+edges] <Gouraud+Edges>: _oCommand: _shademode Current mode: Gouraud+EdgesEnter option [2D wireframe/3D wireframe/Hidden/Flat/Gouraud/fLat+edges/gOuraud+edges] <Gouraud+Edges>: _oCommand: surftab1Enter new value for SURFTAB1 <6>: 8



Invoke TabSurfInvoke TabSurf

Command: _tabsurfCurrent wire frame density: SURFTAB1=8Select object for path curve:Select object for direction vector:

Object forPath Curve

Object for Direction Vector

Surface is Quite COARSE → Change Resolution



Increase SurfTab1 ResolutionIncrease SurfTab1 Resolution

Command: surftab1Enter new value for SURFTAB1 <8>: 36

Command: _tabsurfCurrent wire frame density: SURFTAB1=36

Select object for path curve:Select object for direction vector:

Looks Much Better



RuleSurf on RuleSurf on EllipsesEllipses



Invoke RuleSurfInvoke RuleSurfCommand: _rulesurf

Current wire frame density: SURFTAB1=36Select first defining curve:

Select second defining curve:

First Defining Curve

SecondDefining Curve



EX15-10 – Pedestal ConeEX15-10 – Pedestal Cone 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



All Done for TodayAll Done for Today

DoNutsAnyone?



Bruce Mayer, PELicensed Electrical & Mechanical Engineer

[email protected]

Engr/Math/Physics 25

AppendiAppendixx

6972 23 xxxxf



EX15-10.1EX15-10.1 Command: snap

Specify snap spacing or [ON/OFF/Aspect/Rotate/Style/Type] <10.0000>: 5

Command: '_layer Command: z*Cancel*

Command: cCIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]:Specify radius of circle or [Diameter]: dSpecify diameter of circle: 35

Make Blue Obj Layer



EX15-10.2EX15-10.2

Move UCS and Make 2nd circle

Command: ucsCurrent ucs name: *WORLD*Enter an option [New/Move/orthoGraphic/Prev/Restore/Save/Del/Apply/?/World] <World>: mSpecify 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: ucsCurrent ucs name: *NO NAME*Enter an option [New/Move/orthoGraphic/Prev/Restore/Save/Del/Apply/?/World] <World>: mSpecify new origin point or [Zdepth]<0,0,0>: zSpecify Zdepth<0>: 10Command: cCIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 0,0Specify radius of circle or [Diameter] <17.5000>: dSpecify diameter of circle <35.0000>: 35



EX15-10.3EX15-10.3

Improve SurfTab1 Make Ruled Surface

Command: surftab1

Enter new value for SURFTAB1 <6>: 60

Command:Command:Command: _rulesurfCurrent wire frame density: SURFTAB1=60Select first defining curve:Select second defining curve:Command:

Next



EX15-10.4EX15-10.4

Build Cone in 10-High UCS• Make 60 segments to

Match Base

Command: _ai_coneSpecify center point for base of cone: cenofSpecify radius for base of cone or [Diameter]: dSpecify diameter for base of cone: 35Specify radius for top of cone or [Diameter] <0>: dSpecify diameter for top of cone <0>: 20Specify height of cone: 30Enter number of segments for surface of cone <16>: 60

Documents

[email protected] ENGR-22_Lec-26_SurfaceModel-1.ppt 1 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Bruce Mayer, PE Licensed Electrical