CompuServe Thread

#AutoCad Solids

3 messages in this thread
#60575From: MICHAEL BATESOct 7, 1993 1:46 AM
First of all, this forum is great! Guys like John Tissavary, Greg Pyros, Martin Foster, James Murphy, ….. and the Yost group are just fantastic and can't realize how helpfull they are. I've learnt more by scanning this forum during the last couple of months than I could have imagined. Now to my question: A friend can draw a lawnmower in AutoCad solids (AME 1.0) in a couple of hours. He is much faster than me at drawing 3d objects but can only draw in ACAD. All the objects in the mower will shade fine in ACAD. I make sure all objects are meshes and explode them to the lowest level. I then DXF them by entity and load them into 3ds R2.01 one at a time. The problem is, I am losing faces. Fillet Radii (?radiuses), tubes, hemispheres, etc. come in great. However, some flat areas between them will be missing faces in 3ds. I have increased and decreased the weld-threshold, but the problem persists. Any advice at all will be appreciated!
#60581From: John TissavaryOct 7, 1993 2:57 AM
Thanks, Michael. I, too, learn so much of what I know on this forum. As for you missing face problem, this is often a case of inverted normals (facing away from the camera). If a SURFACE/NORMALS/OBJECT UNIFY… /OBJECT FLIP doesn't work, try applying a double sided material to the dxf'd object. If you want to avoid long rendering times you can flip the normal one by one, but this is time consuming. There is also a way of creating objects in AutoCad that will have the normals facing the same way when DXFing, but I don't know how off hand. Hope this helps, John Tissavary (La Luna cie)
#60593From: Bruce MeikleOct 7, 1993 8:24 AM
This is a probblem in the way AME solids deal with surface normals. Your faces aren't missing, they're just facing the wrong way so they come out invisable when you render them. You have two choices: – You can go through the faces one by one to find out which ones are missing and use the 3DS flip normals feature to fix them. This is super tedious. – You can turn Force Two-Sided on when you render and the missing faces will magically appear. Alternately, you can make all of the materials that you use in the scene into Two-Sided materials. Both of these methods, however, will increase the time required to render your scene I hope this helps you. Bruce Meikle