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Reco
11-25-2011, 02:29 AM
For radiosity rendering I mostly use Fprime or Kray, but now and then I feel a need in order to master Lightwave internal radiosity render. Until this day I have not succeed due to accumulated render time. ( I can fake it with background radiosity and lights for bouncing rays).

Before I start, I will just mention that I have the “Lightwave 9.6/10 Radiosity Guide” by Tom Bosscharert.

System:
Intel Core 2.8 GHz
12GBB ram
64 bit Windows 7 Professional

General settings:
Resolution 1280x720
Perspective camera
photoreal blur

Basic Radiosity settings:
Enable Radiosity
Monte Carlo
Interpolated
Cache/Automatic
Animation/Frame Steps 5

When I start the render, the fist frame takes 10 minutes to complete. The next will take 10 seconds more, and the frame after that another 10 seconds etc. After a while a frame takes 20 minutes to render, even if nothing much has changed in the scene.

It seems like something I building up during the render. I suspect it has something to do with the Cache.

If I stop the rendering in the middle of the process (Lets say frame 50), and restart it again on frame 51, the render time is the same as the first frame. It seems like something has been reset. The problem with stop and restart is that the radiosity will not match.

Please reply if you have a solution or any sorts of advice.



Reco

tudor
11-25-2011, 03:18 AM
Are you animating the scene or making static scenes?
I would try to work with final gather or monte carlo set to interpolate points.

The cache works nice as long as you do not use animated objects. Non deforming objects are better than joint deformed objects.

Mitja
11-25-2011, 03:21 AM
Looks like you are using animated cache (animation checkbox). This should be used only if you have moving objects, I guess this is you case. Growing render times are a normal thing, since the engine adds samples every frame to avoid flickering and artifacts.

Reco
11-25-2011, 04:29 AM
Thank you both
I am using "animated cache" since I have moving objects in the scene.
I hoped there were away around this problem. It is useless if a long animation starts with a five minutes frame and end up with one hour.

Guess I have to go back to Fprime and Kray again.


Reco

biliousfrog
11-25-2011, 04:40 AM
Just as an FYI, Tom's radiosity guide covers the increasing render times and offers suggestions for limiting it, perhaps it's time to re-read it.

Netvudu
11-25-2011, 04:41 AM
what about using non-animated radiosity cache for the environment pass, and use a simple occlusion pass for moving objects?

Reco
11-25-2011, 10:14 AM
Thank you for your reply


Just as an FYI, Tom's radiosity guide covers the increasing render times and offers suggestions for limiting it, perhaps it's time to re-read it.

Tom's guide is a very good one. I have gone trough it several times during the years, and some refreshing as well as just recently. I will do some test regarding the baking options.




what about using non-animated radiosity cache for the environment pass, and use a simple occlusion pass for moving objects?

Well. this sounds like a good idea. I will give it a try


Reco