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Autodesk Multimedia Forum · Hware/OpSys/video

#lofted screw threads?

12 messages in this thread

#98321From: bill "digr" lundeenApr 22, 1994 12:34 PM

hi all. been having trouble creating realistic screw threads. i've tried to do this in the lofter by lofting a triangle around a helix path but the shape gets rotated as it travel around the path. any suggestions? thnks, bill lundeen 75720,554.

#98327From: MARTIN G FOSTERApr 22, 1994 12:51 PM

William, PMJI, try changing the 3ds.set parameter thus: loft-banking=off

#98442From: bill "digr" lundeenApr 23, 1994 5:34 PM

ah hah! thanks, i'll try that. sounds like it will work. so many parameters! so few brain cells!

#98334From: Jim LammersApr 22, 1994 1:33 PM

>>but the shape gets rotated as it travel around the path<< I think Martin Foster answers this in the next message. If you still get banked lofts after fixing the 3ds.set file as Martin recommends, let us know… Jim

#98349From: Jonas Ruikis [ADESK]Apr 22, 1994 3:41 PM

William, << screw threads.. >> I saw Nik Grant do this recently. Maybe he'll jump in today..Nik? jonas[adesk]

#98435From: Angelo Guarino [DTI Inc]Apr 23, 1994 3:53 PM

Will, >> been having trouble creating realistic screw threads. i've tried to do this in the lofter<< Will … I wouldn't do screw threads in the lofter. I would use bump mapping. Have you tried this approach? Ang

#98443From: bill "digr" lundeenApr 23, 1994 5:36 PM

Ang, nope didnt think of that! i used bump mapping in the same scene for another effect but somehow didn't think to use it for the threads. thanks, i'll try it out. bill.

#98841From: Chris JohnstonApr 26, 1994 10:20 PM

Bill: I've done screw threads with a bump map and it looked pretty good. I found that a bump map with a series of vertical lines (actually vertical greyscale gradients) worked better than one with diagonal lines intended to create the spiral thread. I was having trouble with aliasing on the diagonal lines and I found that a map that had parallel lines wouldn't show the aliasing, but at any angle away from dead on axis the grooves look like spirals anyway. Chris

#98874From: Angelo Guarino [DTI Inc]Apr 27, 1994 8:36 AM

Chris, >> I found that a bump map with a series of vertical lines (actually vertical greyscale gradients) worked better than one with diagonal lines intended to create the spiral thread.<< Good suggestion … wise modeling approach .. I like it! Ang

#98959From: Chris JohnstonApr 27, 1994 8:23 PM

To paraphrase a famous comedian, accuracy is the key – when you can fake that, you've got it made… Chris

#99398From: bill "digr" lundeenApr 30, 1994 2:03 PM

thanks for the great info. ive got lots of new things to try now! later.

#99625From: Chris JohnstonMay 2, 1994 8:25 PM

Good Luck! Chris