CompuServe Thread

Jez, >> What I end up with when I render the cylinder in 3DS are the two ends of the cylinder but no "cylinder walls". << sounds like the face normals are flipped. There's several commands that may help. The easiest one is to just use a 2-sided material (or render with force 2-sided on). The next simplest is to try surface/normals/unify. If that doesn't work you can manually do surface/normals/face flip for each offending face.

>>I'm using AutoCAD V12 (windows) and 3DS V4. When I create a 3 d model in AutoCAD (say a cylinder using the Model/Primitives option) the rendered image appears correct. However, when I DXF the same cylinder to 3DS, it doesn't render ok. What I end up with when I render the cylinder in 3DS are the two ends of the cylinder but no "cylinder walls".<< Jez, I am assuming that you are creating solid models in r12. In order to have the mesh information transfer into 3DS you first have to use the Display/ Mesh command ( SOLMESH) in order to create faces on your solid. You may also want to play with your SOLWDENS variable, your mesh density is directly related to this variable; the higher the number the more faces you will have on your solid. Also, after you import your solid mesh information into 3ds you will need to unify your normals. Let me know if this solves your problem, Roy Baker.

Sounds to me like your face normals are turned inward instead of pointing outward. A quick experiment to prove this theory would be to assign a 2-sided material and render. If the sides show up then you will have to either live with the 2-sided material or flip all those faces so that their normals are pointing outward. Face normal abnormalities are inherent in working with Autocad, although I have never had this problem with primative objects like a cylinder. Lee

Looks like you need to MESH your object before you DXF it. It has nothing to do with the normals in 3DS. This will solve your face problem.

Jez, In Autocad, do a "solmesh" on the solid, you may need to increase "solwiredensity" for smoother curves. As an option you can exploded the meshed solid, do a "dxfout" and use the "Entities" option so that the dxf file only contains the mesh info. Scott