Flickering reflection problem...

V-Ray V-Ray for Maya Issues
1

I’ve got a problem I’m hoping someone can help me solve.
I rendered out a scene with a dinosaur and found that the light reflected in the eye was flickering.

I went into maya to double check, I turned off other eye geometry just to make sure nothing else was causing the problem, but sure enough, in single frames the reflection suddenly gets much dimmer.
I can’t for the life of me figure this out. I’m using a .98 directional rectangle light and a very dim non-spherical dome light. Rendering without GI.

For reference here is a render of the eye. It looks correct in one frame, incorrect in the next frame, and correct again in the frame after.

I’d love it if anyone had any suggestions as to why this is happening and how to fix it.
I’ve attached a .zip of the scene that exhibits this. Check out the difference between frame 895 and 896

I’m on OSX using vray 3.4.02 in Maya 2016.5

Thanks!!!

flicker_eye.jpg
flicker_eye.jpg1158×358 96.9 KB

reflection_problem.ma.zip (429 KB)

2

The reason for flickering is …wait for it…the geometry has faceted normals :slight_smile:

Also, suggest to set the min aa samples to 2, it will help with very small highlights and things which are of 1 pixel not to disappear in between frames.

3

Oh man. I feel so stupid.
I spent a long time trying to figure this out. I check EVERYTHING.
I think I had an older version of this scene where I had added subdivs, but somehow that got blown away so I guess I never thought to go back in and check if they were missing.

Thanks for helping me figure out a stupid mistake.

Cheers