3.0 Motion blur sampling

[Moriah]

So for the first time we're trying to render our animations with motion blur, and as far as i've read now in 3.0 its connected to the AA samples. Problem is, and i tried everything right now, it's always grainy. I'm using DMC, i have geometry samples at 8, prepass at 3. Default AA for this scene is 1/10 clr 0.015, mb looks grainy, i tried reaching 5/50 and its still grainy. Tried clr threshold, does nothing. Noise threshold at 0.002 - nothing. Increasing min shading rate - nothing. (i have divide shading subdivs off). I tried Embree on and off and nothing. Even turning DR off doesn't solve the issue. With and without GI its still grainy.

Bit desperate right now, any suggestions?

Vray version is 3.05.05 nightly 29th april

[vlado]

Bit desperate right now, any suggestions?

Yes, please send me a scene to either vlado@chaosgroup.com or to our support guys to vray@chaosgroup.com - we'll be able to suggest suitable settings.

Btw you are not using the new "Optical vignetting" setting of the V-Ray physical camera, are you?

Best regards,
Vldao

[bennyboy]

I've noticed with DOF in 3.x there is no longer the ability to control the subdivisions in the phys cam settings. The only place I've seen similar settings is under the Adaptive Subdivision menu...don't think it's the same, though. not sure. It would be nice, though, to still be able to control motion blur and dof separately from AA.

[joconnell]

Accuracy or sampling of the position of your geometry is all AA, motion blur is just sampling the position of your geo as it moves through the frame over time so very similar in concept to aa, lastly DOF is more position sampling again, just wiggled or rotated by the radius of your dof. They'll all AA functions, the guys just decided that since they do the exact same thing (fire camera samples) that they could be removed from the ui to keep things simpler.

[vlado]

So in case anyone else comes across this thread; please, stick to universal settings (though you can use less than 100 subdivs) + min. shading rate. You won't go wrong.

You may think you can optimize your sampling better than V-Ray; you might succeed in one case out of ten.

Oh yes, and leave "Divide shading subdivs" enabled

Best regards,
Vlado

[Deflaminis]

I'm having similar issues, even with the universal settings. There's some weird interplay between noise, motion blur samples, and light subdivs for me as I am learning vray 3. When I raise the subdivs to 1/100 (universal) I no longer get a noise free lighting and gi render element, though it does seem to improve the motion blur, but not make it noise free. After I do this (1/100) If I increase the subdivs on my vray light (dome w/ hdri) I can hit 1000 light subdivs (max setting) which solves 75% of the motion blur noise issues but now there are noise in lights and gi issues and I'm at the ceiling for subdivs so I'm a bit stuck. Otherwise I guess I can use the global subdiv multiplier but seems rough to go back into everything and divide them by 2. Not sure how to proceed.

[vlado]

Not sure how to proceed.

Get me a scene and I'll be able to suggest some settings. There are no differences at all between V-Ray 3 and 2 in that regard.

Best regards,
Vlado

[Deflaminis]

Thanks Vlado, I appreciate your time.