AutoCAD 3D Modeling: 3D Meshes
August 4, 2003 3D Polygon meshes are surfaces that consist of several flat
faces. There are some commands that can create such surfaces.
One of the rarely used commands is called 3DMESH. This command
is difficult to use but very powerful. It is mainly used by
programmers. Here you will use the command to create a surface.
Later the PEDIT command will be used to close and smooth the 3D
mesh.
Notes:
► This tutorial is designed for AutoCAD 2004 though might be
applicable for other releases.
► In this tutorial user entries are in boldface.
► The
8
symbol represents pressing Enter.
1. Download
r16_3d_meshes.dwg
Note: If you are using AutoCAD 2002 or an earlier release
download r15_3d_meshes.dwg
2. Open the drawing in AutoCAD [Figure 1].
Figure 1
3. Switch the shade mode to Flat Shaded.
4. Invoke 3DMESH (Draw > Surfaces > 3D Mesh).
5. The model that we are using as the skeleton of the 3D mesh
consists of 4 levels and 4 columns. Thus answer the first 2
prompts as follows:
Enter size of mesh in M direction: 48
Enter size of mesh in N direction: 48
6. Click 0,0,0 as the first mesh vertex. Then click on the
vertices of the same column from bottom to top. The points of
the first column are in red. Click on the points of the second
column (green points) from bottom to top. Go ahead on other
columns one by one. An open surface is created [Figure 2].
Figure 2
7. Freeze all layers except the current layer.
8. Invoke PEDIT.
9. Select the 3D mesh.
10. Select Mclose option. The surface is closed now [Figure
3].
Figure 3
11. Select the Smooth surface option. AutoCAD increases the
number of vertices and changes the shape of the 3D mesh [Figure
4].
Figure 4
12. Exit PEDIT.
13. The SURFTYPE system variable defines the smoothing method
applied by PEDIT command. The eligible values are 5, 6, and 8.
Alter the SURFTYPE to 8.
14. Invoke PEDIT. Select the 3D mesh.
15. Select Smooth surface option. A new shape is created
[Figure 6].
Figure 5
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.
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