FG Mapping Issue / splotchy shadows

[ChippedTooth]

I realized I put this in the wrong forum earlier:

 

I have been trying to render an animation and have been running into an issue I am hoping someone can help me with.

 

I am rendering an interior animation with Mental Ray using FG and GI. The scene is lit with a daylight system and photometric can lights and finally mr Portal lights.

 

First I calculated the GI and all is good. I calculated the GI photon map and switched to read only.

 

Then I turned the photometric lights on and figured out the Final Gather solution and again...everything looked good...for the still render. I then incrementally added the FG points every 10 frames and saved the FG map. Then I turned on the mr portal lights and switched the renderer to read only for the FG map and when the first frame of the animation processed it had splotches that were not in the test renders.

 

Any ideas?

 

I wonder if I need to up the increments of my FG map? I did try every 20 frames and every 10 frames and had the same issue. I also tried ditching the mr portal lights, adding and dropping bounces to the FG --- and everything I try ends with splotches still that were not visible on the test render.

 

Thanks for any help or suggestions you have!

 

Andrew

[Justin Hunt]

post your render settings and a frame

 

jhv

[ChippedTooth]

Attached is the image of my settings and the results. The FG map was created incrementally at every 20 frames. The GI map is the same in both images. Thoughts?

[Justin Hunt]

Looks like a photon radius issue. Try reduce the photon radius, shoot more photons and turn ON Optimize for Final Gather. Increase the Max trace Depth to 100 and Max Reflection & Refractions to 50 (this will bounce the photons around more)

 

Leave the FG Diffuse Bounces @ 0 as any extra bounces are discarded any way.

 

Is the camera moving? If so rather use the "Project Points along the Camera Path" method. Although you will have to increase the FG Density to compensate of the smaller resolution from dividing the screen up.

 

jhv

[ChippedTooth]

Thanks! I'll give it a shot and keep you updated.