I tried to search for this issue but can't find anything, so if there's already a thread about it I apologize.
I'm using Mental Ray and when using 2D geometry (from the built-in library) I got color splotches all over the scene (not only forest objects). It seems related to the forest material shader.
Here's an example :
Appart from removing the forest material shader and applying directly the standard to the geometry I can't find a way to avoid these color splotches, is this a known issue and is there a workaround?