Figure 1
1. Download
r16_edge_surf.dwg
Note: If you are using AutoCAD 2002 or an earlier release
download r15_edge_surf.dwg
2. Open the drawing in AutoCAD. The drawing consists
of the Wireframe model of a tent. The numbers beside lines and
arcs are used to help you click on the proper elements [Figure
2].
Figure 2
3. Make Surf01 the current layer.
4. Explode the base rectangle 1-5-7-6.
5. Assign proper values to SURFTAB1 and SURFTAB2:
Command: surftab1 8
Enter new value for SURFTAB1 <6>: 24 8
Command: surftab2 8
Enter new value for SURFTAB2 <6>: 24 8
6. Invoke EDGESURF (Draw > Surfaces > Edge Surface).
7. Click the curves 1, 2, 3, and 4 respectively. A 3D
mesh appears in drawing area [Figure 3].
Figure 3
8. Switch to Surf02 layer and freeze Surf01.
9. Invoke EDGESURF and construct a surface on curves
7, 8, 3, and 9 [Figure 4].
Figure 4
10. Switch to Surf03 layer and freeze Surf02.
11. Use a similar method to cover the base with a
surface (curves 1, 5, 7, and 6) [Figure 5].
Figure 5
12. Make Surf04 the current layer and then freeze
Surf03.
13. Split the line 5 into two lines. Use Break at
Point method.
14. Invoke EDGESURF. Click curves 2, 8, and the two
portions of 5 [Figure 6].
Figure 6
15. Make Surf05 the current layer and then freeze
Surf04.
16. Split the line 6 at the point of intersection with
arc 11.
17. Invoke EDGESURF. Select curves 4, 10, 11, and the
small portion of the line 6 [Figure 7]. You may need to zoom
into the drawing.
Figure 7
18. Move the UCS origin to the front top point of the
tent. Then rotate it 90 degrees about Z and X axes respectively
[Figure 8].
Figure 8
19. Use the MIRROR command to create a mirrored copy
of the last surface with respect to the Y axis [Figure 9]:
Command: mi 8
MIRROR
Select objects: 1 found
Select objects: 8
Specify first point of mirror line: 0,0 8
Specify second point of mirror line: 0,1 8
Delete source objects? [Yes/No] <N>:
8
Figure 9
20. Thaw all layers. Enable Gouraud shaded. Switch to
WCS [Figure 10].
Figure 10
Alireza Parsai is the founder of cadpanel.com. He is a
mechanical engineer with more than 12 years experience with
AutoCAD. Alireza is an Autodesk Authorized Author, the AutoCAD
consultant for Al Khawarizmi Institute, a contributing editor
for Augiworld magazine, a writer for CAD Digest, an instructor
for AUGI Training Program, and an elected speaker for Autodesk
University 2002. He has written 7 books in Farsi, 3 booklets in
English, and more than 30 articles for different magazines and
newsletters. You can reach him at
alireza.parsai@cadpanel.com or visit his website
www.cadpanel.com.
