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View Full Version : Radiosity/SDK fixed in 8.1?

Brent Turbo
06-08-2003, 07:51 PM
Here's a question for anyone who's familiar with the SDK and all that junk....

There was a problem in XL7 where radiosty data couldn't be passed along in the SDK (or that's what I gathered from what people were saying, anyway). That meant that GI generated lighting, like HDRI images or luminous materials couldn't affect plugins like Chanlum and Translucent Pro. Is this fixed with 8.1, or is this still an issue? I realize that this could be worked around with light exclusion and stuff, but it would be nice if this worked for the sake of quick setups.

Thanks!
imashination
06-08-2003, 08:10 PM
Its just the way it is. Theres so much data in the radiosity calculations, that for a translucency plugin to process it all, It would be pretty damn slow.
Brent Turbo
06-09-2003, 01:50 AM
Thanks dude! I've always been curious about that, and now I know.... I remember some plugin writers a while back complaining that the problem was just that Cinema's SDK couldn't output all the info they needed, but perhaps that's in their best interest...
imashination
06-09-2003, 11:47 AM
Think about it this way (im simplifying here) A light source shoots out one ray of light. A Radiosity system typically shoots out 300, each of these rays subdivides into another 300, then 300 again.

Thats 27 million

Sometimes you subdivide these rays once more, thats 8 billion ;-)

Theres a million other things you need to take into account, but it should give you some reason why there is no radiosity enabled translucency. I can immediately think of a faster way to do it, but I like scare-mongering :)
MJV
06-09-2003, 08:11 PM
I believe that Chanlum works by sampling illumination on the object, not light direction, so it should in theory be possible to make it work with radiosity.
Brent Turbo
06-09-2003, 08:31 PM
If nothing else, it could be limited to only sampling 'first order' light transmission, and not the subsequent bounces. That way, you could use chanlum with an HDRI image and get just the results you want without a huge setup time. It seems like this wouldn't be a massive calculation if plugins were allowed to take only as much as they need from the radiosity calculations.
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