CompuServe Thread

#Application/Function ??

4 messages in this thread
#123341From: gregSep 12, 1994 7:15 AM
To All, We are interested in 3D Studio to do lighting simulations on clear plastic parts for evaluation before tool-build. Light is directed into the part and reflected internally within the part off various angles, and directed to a painted surface at the end of the part. This painted surface is visable to the operator. The idea is to light the painted surface, not to make the entire plastic part light. Any comments concerning the use of 3D-Studio for this application are welcome. Thanks Greg Haminger \exit [A/exit
#123348From: David J. MarksSep 12, 1994 8:41 AM
>> The idea is to light the painted surface, not to make the entire >> plastic part light. I interpret from your description that you are most concerned about how the light from certain angles reflects off the part and hits a viewing surface. Is this for some sort of optical comparison? In any event, what you describe is a ray-trace effect, where each "ray" of light follows a path from a light source through various reflections and refractions finally landing somewhere in the field of view. (Purists please forgive this over-simplified description!) As it presently stands, 3DS does not have this capability. Michael Bassier here on the forum is working on a raytrace engine for 3DS that may have some use in your application. – Dave
#123434From: David WrightSep 12, 1994 6:32 PM
I believe I have some experience with problems your facing. The short answer is "probably not". background is automotive lighting – instrument clusters, exterior & interior lighting – if what you want to know is how much light and where – quantitativly or qualitativly then you are better off starting with a "real" Optical Computer Aided Design program. but even these (at least 2 years ago) didn't realy do a decient job of giving you a good idea of how well a given part would work. some of the problems come from computer model of light source vs the real thing (distribution pattern) the model of the interface ( – like "bidirectional reflectance distribution function") a bunch of other stuff that I've forgotten, and of course the fact that the real human eye is more sensitive to subtlties than a CRT is capable of displaying.. Since this is some what old information – i suggest you talk to some of the vendors, but hold onto your credit card – untill you see the stuff work for real. good luck Dave Wright – Wyeknot, inc.
#123517From: Paul AdelsonSep 13, 1994 8:30 AM
Greg, So far as I know, the information David Wright sent you is still correct. Unfortunately, understanding how light acts inside plastic parts is still more of an art than a science. If you find out otherwise, please let us know — I'm sure there are several people here who would be interested!