LC #42 Pipers Alley

View Full Version : Processing Lights for every frame

03-05-2002, 10:30 PM
Is there any information as to why 3D Studio Processes Lights for every frame(during a sequence) and then sometimes only processes them once(in the begining of the sequence).

I am currently working on a walkthrough of a large Science facility.
About 4 weeks into the the project I noticed that when I rendered a sequence of frames the Lights were processing before every frame. I checked an earlier file and found that the lights would only be processed once in the very beginning of the render. I narrowed the problem to my animated door. If I turned the doors off the render would only process the lights once.

Has anyone else seen this before? This issue increases my render time 6 fold. And yes, the easy way is to turn the doors off when I don't need them but I am looking for more of a technical answer.

-3D Studio Max and Viz 4
-Just scanline rendering w/ 1 raytrace direct, 30+ omni and 30+ direct.
(no radiosity..I am still doing it the old way)


03-05-2002, 11:57 PM
It depends if you moved an object, then Max has to recalculate all lights solution ( he cannot re use the same shadow solution if something move). If you just move a camera trough a scene, Max will only calculate the lights once

03-06-2002, 12:21 AM
Thanks you for that info. I start to forget the basics of rendering after being consumed by my own work.
However, I do have one science lab(isolated in its own file) that has no animated objects; and it is still calculating the lights for every frame.

03-06-2002, 05:50 AM
Looks like we will be able to bake our lighting solutions into textures easier in max5,.. man where was that 6 years ago?
Besides lightscape..

RE your science lab, could a raytrace material, or opacity map in front of a raytrace light be the source of that forced re-calc?


03-06-2002, 11:04 PM
After to many hours of figuring this out, this is what I found:

In Max 4.2 the frames would only prepare the lights when there was an animated object in view of the camera. When the scene was static the frames rendered without preparing lights(except for the first frame.)
...Perfect result. What I need and what everyone told me would happen.

However in Viz 4, this was not the case. For some reason the same scene, even in the static areas, would still insist on preparing the lights for every frame. Stupid Viz 4.

I am rendering everything in Max from now on.

Thanks for all your help guys,

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