Posted by Kevin Matthews on November 05, 1998 at 17:42:23:
In Reply to: "Real" lighting specs / analysis posted by gary veasy on November 05, 1998 at 09:06:48:
I like the question you're asking. It is a very real and fairly deep question. Here's my general response (begin sermon...).
There is no fundamental reason that you can't quickly whip out a simple space in DesignWorkshop, plop in accurate light sources in a few seconds, and then render the scene in a few minutes with photometric accuracy using Radiance Online.
And that's exactly the direction we're headed in.
However, for all the usual picky implementation issues related to developing digital tools, getting to that nirvana is going to be a gradual process. For example, if you don't know within 10% how reflective the paint, floor, and ceiling tiles are, it really doesn't matter how accurate the light sources are -- the results will be numerically meaningless.
Then there's the issue that what you see on a computer screen is ALWAYS numerically meaningless -- if it is a rendered image. Radiance uses floating-point values for each color at each pixel of an image, so the many orders of magnitude of brightness in a real scene can be stored accurately inside, BUT, when those floating point colors are converted to integer pixels and then beamed across the phosphors of your monitor, qualitative is all you will see.
For some examples of how you CAN get numerical display in an image format, follow the link below to a secret preview page.
Then there's the issue of _which_ lighting fixtures you want to render with accurately. Believe me, one or two won't be enough. You may want just one or two, but the next guy will want a different one or two. Again, there's no fundamental problem -- but assembling an accurate catalog and making it easily accessible adds up to major person-hours, really fast.
Anyway, if you have both the need and ability for total numerical simulation at the do-it-yourself prototype level, then I would definately second Peter's advice, and "read the book". As we do at Artifice, a few times a week, even though I've been working with Radiance for more than ten years now...
Alternatively, work with us, and we can make constant, slow, incremental progress, with real tools you can really use (...end sermon).
To be more direct, what four specific lighting fixtures would be most useful to you in the next month? Tell us, and we will do our best to support them within the next few days. As we can fit it in around some of our other special projects (product textures, anyone?).
Onward, and upward! ; )