If you are rendering a scene with final gather and the lighting flickers, follow these steps:

1. Enable the Optimize for Animations option under the Final Gathering Tracing section, Final Gathering Tracing subsection in the Indirect Lighting tab of the Render Settings: mental ray tabs. The Optimize for Animations option sets the final gather mode to multiframe.

   See Final Gathering Modes in the mental ray for Maya reference guide for more information.

2. Set the Render Mode to render final gather maps using this command:

   setAttr mentalrayGlobals.renderMode 3;
   

3. Set the scene to render a representative subset of frames or a coarse version of the animation.
4. Set Rebuild to Freeze under the Final Gathering Map section of the Indirect Lighting tab of the Render Settings: mental ray tabs.
5. Set Render Mode to full render using this command:

   setAttr mentalrayGlobals.renderMode 0;
   

6. Fully render the scene.
   Note

   While this workflow avoids flicker, some parts of the scene may still suffer in quality if an insufficient number of final gather points is found.