Refracting light through glass colour change

[thatch]

Take a close look at this image of 2 frames of animation, the light coming through the glass changes from being the nice green colour it should be to not being green, it happens randomly through out the animation on our render farm. ive checked my material and geometry and they are fine, maybe its a bug? Im using a standard max direct light with area shadows.

http://www.ahd-imaging.com/download/Shadow_Problem.jpg

[vlado]

Which 3dsmax/V-Ray version is this?

Best regards,
Vlado

[thatch]

3ds max 8 and vray 1.5 RC2

[vlado]

You can try to render this as a test in RC3 and see if you still get the error - I think something like that was fixed.

Best regards,
Vlado

[DaForce]

Just remember in RC3 you have the issue of glass materials in multisub materials, where the affect shadows doesnt work. So if its just a single material then your ok. Otherwise you will need to wrap it in a vrayblendmtl first then put that in the multisub

[Clifton Santiago]

I had this exact problem a couple weeks ago on an animation. It turns out it was caused by this error "Scene bounding box too large, possible raycast errors". The fix was scaling the model down until this error stopped happening. An additional problem is you will need to scale your animation down by the same factor you scaled your model.