CompuServe Thread

Lighting Candlepower?

7 messages in this thread
#86608From: Joe Simons, AIAFeb 25, 1994 2:33 PM
Hi Gary- Two questions: Is it possible to equate your lighting levels for spot lighting (as well as the others) to candlepower? Second, is it possible, with the lighting features available, to simulate continuous cove lighting (no hot spots)? These questions are the result of conversing with my electrical engineer. He thinks (and I do too) that it would be very nice to be able to ACCURATELY light a space to see what the lighting charateristics really are. As it is, I try to do what "looks good" for the rendering, and it pleases the clients and my boss, but he (the engineer) brought up the point, and I thought it was a pretty good one. Soooooo, I thought I'd pass it on. Thanks for your time- Joe
#86675From: John TissavaryFeb 25, 1994 7:01 PM
For continuous lighting, have you tried using rectangular spots? Have you tried projector spots? I am not an architect or engineer, so I don't know exactly what you folks need, but it seems the "no hot spots" issue could be covered by either of the above techniques. Sounds like a good wishlist request, though =-) John Tissavary (La Luna cie)
#87261From: Joe Simons, AIAFeb 28, 1994 9:25 AM
John- Thanks for the reply. I'll give it a try. Joe
#86718From: Yost GroupFeb 25, 1994 9:48 PM
You should be able to do continuous lighting as long as your hotspot is 0 and your max light value is less than 160,160,160. If those two cases are true, you'll have no hotspots. Re accurate lighting… 3DS is a production animation system, which uses empirical methods to get fast, aesthetically-pleasing results. Accuracy does't really fit in. We've been looking at ways to IPAS-ize those kinds of functions in the future, but for now… – G
#87259From: Joe Simons, AIAFeb 28, 1994 9:25 AM
Gary- Thanks for the tip on even lighting techniques; it should help a lot! As for the other…..oh well, maybe someday. As it is, I'll just fake it. I guess I thought that it would be as easy as assigning a candlepower to a light source, and using lighting manufacturers throw diagrams to generate hotspots and fall-off. I have since found out that that thinking is an over-simplification of the issues involved in 3D lighting. Thank you very much for the speedy reply. Joe
#86793From: Phillip L. MillerFeb 26, 1994 7:21 AM
Using a recangluar spotlight with an extreme aspect ratio and reducing the hotsopt to zero is as best as you an do with R3. The light intensity is still originating from a point source however, so a true cove light is very difficult to acheive – yes, we NEED linear light sources AND parrallel lights! If you absolutely need the effect, one workaround is actually to use a projector light (excluding everything but the wall and placed far enough away to cast even illumination) that is using a vertical gradient bitmap. This does work and makes others ask how you did it.
#87258From: Joe Simons, AIAFeb 28, 1994 9:25 AM
Hey Phillip- Wow! These are some great techniques! Thanks for the reply, and it looks like I'm set. Joe