#3d Faces
5 messages in this thread
Thanks for the info Michael, that worked fine. I'm knew to 3D Studio so you may
hear from me from time to time. One other problem that I have been having with
DXF imports are the faces. It seems that sometimes the 3dfaces are only
rendered on one side. I think that I read something about this in the tutorial
and they is a way to render both sides. I think the way to correct this is to
make sure that when I apply the face in AutoCad, the UCS is positioned so that
the face that you what redered is the front and not the back. If that makes any
sense please let me know.
The trick is to create the faces in a clockwise direction, as you look at the
side that you will want to see. Thus, you can also create the faces in a
counterclockwise direction, if you are looking at what will be the back of the
face. The UCS is irrelevant to the situation.
DXF imports into 3D Studio is full of those kind of annoyances. You can chose
"force Two sided" I believe in the rendering dialogue box, but that is
computationally expensive depending on the complexity of your model. You can
also load the ACAD Library of materials before you import the dxf file and ACAD
colors will be assigned automatically with materials that are two sided. Or
you can walk the faces and manually turn the face normals. Tedious to say the
least. The Best solution is to avoid it entirely. Most of the time when I
want to import a model from ACAD I develop it as a solid with AME then SOLMESH.
DXF out and most of the time you get really clean incoming models with the
normals unified.
If you are creating 3D FAces in ACAD, be sure to proceed in a clockwise
direction relative to the UCS. Glad to be of some help <G>.
Michael B.
Dale,
Although the "Clockwise-creation" method for 3DFace normals is correct it is
not very practical (unless you employ LISP) and is only relevant for
isolated/non-welded faces.
Your best bet is to model your faces (in AutoCAD) so that they share two
vertices with each adjacent face. This will allow 3DS to weld them together
and unifying the mesh's normals. Now the mesh may still be facing the wrong
way, but a quick object/element flip will put it right.
– Phil
Phillip and Dale,
We have a product called BlockSOLID ($295) that run inside ACAD and joins 3D
faces, poly-meshes (RULESURF, REVSURF) and p-face meshes. It also has a
normalization rouitine as well as a lot of other functions .. like surface
offsetting, x-section's, etc. If you are interested in more info, send me your
fax# and/or mailing address.
Ang