Engineering 22
Surface
Modeling - 1
Bruce Mayer, PE
Licensed Electrical & Mechanical Engineer
BMayer@ChabotCollege.edu
Engineering 22 – Engineering Design Graphics
1
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
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
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
Invoke Surface-Shapes
Surfaces
ToolBar
 Or Command Line
• ai_XXX
– XXX = box, wedge,
pyramid, cone, etc.
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
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]:
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
Draw 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_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:
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
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
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
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
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
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
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
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>:
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
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
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
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>:
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
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
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
RevSurf Example
Axis of
Revolution
Form to
Revolve
Engineering 22 – Engineering Design Graphics
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 Make Bowl
with a Nice
Base by
Revolving a
Closed-Form
About a
Vertical Axis
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
Set SHADING & SurfTab
 Increase the
WireFrame Density
Command: surftab1
Enter new value for SURFTAB1 <6>: 36
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
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]:
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
Change to IsoMetric View
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
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
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
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>:
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
SurfTab Comparison
 SurfTab2 = 6
Engineering 22 – Engineering Design Graphics
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 SurfTab2 = 12
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
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
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
Invoke TabSurf
Object for
Direction Vector
Object for
Path 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:
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
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
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
RuleSurf on
Ellipses
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
Invoke RuleSurf
First Defining
Curve
Command: _rulesurf
Current wire frame density: SURFTAB1=36
Select first defining curve:
Select second defining curve:
Second
Defining Curve
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
EX15-10 – 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
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
All Done for Today
DoNuts
Anyone?
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
Engr/Math/Physics 25
Appendix
f x   2 x  7 x 
9x  6
3
2
Bruce Mayer, PE
Licensed Electrical & Mechanical Engineer
BMayer@ChabotCollege.edu
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
EX15-10.1
Command: snap
Specify snap spacing or
[ON/OFF/Aspect/Rotate/Style/Typ
e] <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
 Make Blue Obj
Layer
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
Command: ucs
Current ucs name: *WORLD*
Enter an option
[New/Move/orthoGraphic/Prev/Restore/Save/Del/Appl
y/?/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/Appl
y/?/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
 Move UCS
and Make
2nd circle
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
Command: surftab1
EX15-10.3
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:
 Next
 Improve SurfTab1
 Make Ruled Surface
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt
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
 Build Cone in 10-High
UCS
• Make 60 segments to
Match Base
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-26_SurfaceModel-1.ppt