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robertoortiz
12-07-2014, 10:26 AM
Hey guys
I am trying to optimize a global illumination test scene I created for animation.

https://www.youtube.com/watch?v=Jf-jw4kD-ss&feature=youtu.be

What is giving me problems is the noise I am getting under the bed.
Any advice on how to improve GI renderings like this one for animation?
Do you do multiple Global Illumination passes using multiple camera before you bake the GI?


I am including on this message the render and GI settings for the project.
Thanks,

-R

MSherak
12-07-2014, 02:01 PM
Well on of the settings you have off is the animation button. This means that every frame is calculating the GI and only storing that frame. Try a new named cache and bake the GI the animation button on and the always option on. This will store the first frame and add to the cache additional samples as the camera moves. Once done add another camera and point it to the problem areas and bake again. This will add more samples in that problem area to the cache which will help when finally being used to render the animation.

Also check out http://www.except.nl/lightwave/RadiosityGuide96/index.htm for a really good explanation on how the basics of GI cache work. It's an older site but the basics are still relevant.

-M

Axis3d
12-07-2014, 03:11 PM
Also, the new version of LW (2015), has 'importance sampling', which may help clean up and focus the sampling better.

prometheus
12-07-2014, 03:44 PM
Also, the new version of LW (2015), has 'importance sampling', which may help clean up and focus the sampling better.

he already had that checked.

it could be that the multiplier is set too low for animation GI 35% raise it back to 100 maybe?
and check animation for cache.

RebelHill
12-07-2014, 04:12 PM
Just bake the scene and then set the cache to locked before you render. No need to activate animated for camera moves.

sukardi
12-07-2014, 05:57 PM
Those are not noise. They are flickers.

You reduce them either by increasing RPE (longer render times) or increasing minimum pixel spacing (faster render times - I know it is counter intuitive). The problem with high pixel spacing is that you loose GI detail in the corners.

Baking the GI without checking animated would also eliminate the flickers but you may run into long preprocessing time - depending on the scene.

I normally quite low GI setting. Then I tighten the details in the corners by running a AO pass (dpkit) and multiply the image together.

erikals
12-08-2014, 04:29 AM
if you use motion blur you can also use this trick to cut render time >
https://www.youtube.com/watch?v=6DxXJoK9kHA

souzou
12-08-2014, 04:43 AM
As he seems to be too shy to, can I recommend RebelHill's GI tutorial on cmiVFX. One of the most useful LW tutorials I've ever watched.

In my early experience of importance sampling in LW 2015 I've found it introduces flicker to GI animations, but I've not had time to do much testing on it yet. Would be interested to see if anyone else has done any testing with it.

robertoortiz
12-08-2014, 07:15 AM
OK guys I am releasing the model here.
Anyway it was done to learn GI.
Just give ma couple of hours.
All I ask is that if you optimize the render to please share your method.

tcoursey
12-08-2014, 08:06 AM
Just bake the scene and then set the cache to locked before you render. No need to activate animated for camera moves.

Like Rebel says change to LOCKED once you've baked the scene. No need for ANIMATION as the camera is all that moves....if you had moving objects you could use ANIMATION. If you have a problem area after baking the scene like mentioned point your camera to that area and BAKE additional information.

You may not need that high of settings once you get the flicker removed (That is with the LOCKED option, once baked). We usually get away with much much lower settings on final animations.

Process for us...
Set appropriate settings for given scene
Set CACHE File
Set to Automatic with anywhere from 10-50 frame steps, depending on camera movement
Bake Scene
Change PreProcess to LOCKED
Render away and enjoy!

robertoortiz
12-08-2014, 09:20 AM
Ok guys,
as promised here is the file.


125945

the files are password protected:
radiosity

I am playing right now with the settings you guys recommended and I will post my results soon.
Anyway just share with us your optimization tips and tricks.

Later I might post another scene.
I have another room- I basemen, I want to share.

tcoursey
12-08-2014, 09:46 AM
Ok guys,
as promised here is the file.


125945

the files are password protected:
radiosity

I am playing right now with the settings you guys recommended and I will post my results soon.
Anyway just share with us your optimization tips and tricks.

Later I might post another scene.
I have another room- I basemen, I want to share.

This is how we would render this scene. If you need the area light speckles to be reduced even further you can up the lighting samples. Just re-bake with these setting and then change preprocess to LOCKED and you should be golden!125946