VRay RT GPU CUDA 3DSMAX2016 motion blur bug

[Moko3D]

Situation: VRay RT GPU CUDA 3DSMAX2016 - either local or distributed RT using either 1 or multiple GTX980ti and/or using either 1 or multiple GTX580
Problem: motion blur will only RT on the initial render after starting a new active render - re-initialize won't produce a new motion blur frame, only killing the active shade render and going again produces 1 more m'blur render.
Same bug whether with embree motion blur on or off.

[vlado]

This is only in ActiveShade mode, right?

Best regards,
Vlado

[Moko3D]

We're not doing any final renders in RT/GPU yet, we still want features (and scene memory) afforded by traditional CPU rendering, so we're using active shade to speed up previewings, shots and animation keying.

[Alex_M]

I was just about to post the same thread. We are currently working on a project where we want to set the motion blur for some objects with the help of RT through Active Shade. However, just the initial frame has the motion blur effects. If we move the timeline slider, everything else updates but motion blur is no longer applied unless we stop the render and start it again. This happens on both CPU and CUDA engines. We're using the latest official build 3.20.03 on Max 2016 SP1 EXT1.

[Moko3D]

Yes, good point, it happens on CPU and CUDA here too.
(Oh and using VRAY3.2 as I didn't put that in the original post.)

[vlado]

Ok, I know this problem is there. It's a bit tricky to solve it in a stable way in Max (it works fine in Modo, for example). I know that the 3ds Max guys are working on a new API that will make this easier to implement.

Best regards,
Vlado