Animated motion blur duration

[briareos_kerensky]

Hello everyone,

is it possible to animate any of the motion blur duration parameters, whether global or per-object? I'm using Max 2020 and V-Ray Next 3.1.
I have a wheel attached to a support; the wheel decelerates to a stop, and then the support moves the wheel out of the picture. I disabled motion blur for everything except the wheel, and as long as the wheel simply decelerates, it's fine. However, the wheel becomes blurred again when is moved by the support, and I don't want this to happen.

I have tried to animate the global parameters in V-Ray > Camera > Motion Blur > Duration and the moblur duration in the V-Ray object properties dialog; neither parameter appears in the curve editor, nor I can add the object's moblur duration as a custom parameter.

I could change the camera exposure but this will make the lighting uneven (and maybe won't eliminate motion blur completely); I tried to output the velocity channel and edit the scene in After Effects (with Re:Vision Motion Blur), but the blurring of the wheel doesn't compose well with the rest of the layers.

[hermit.crab]

Have you tried controlling the motion blur duration through the V-Ray properties (right-click object>V-Ray properties) on a per-object basis?

[Joelaff]

I use that setting, but it always confuses me. Is it a multiplier for the motion blur set in the camera (how I would want it to work)? Or is it an absolute override, in which case what are the units? 1.0 is one frame? (360deg shutter)?

The VrayCamera set to motion picture camera desperately needs the ability to specify shutter angles greater than 360deg. Yes, I know how a rotating mirror shutter works, and I know this is not possible in reality, but neither is creating images on a computer

[briareos_kerensky]

Have you tried controlling the motion blur duration through the V-Ray properties (right-click object>V-Ray properties) on a per-object basis?

Sorry for the (very) delayed answer...yes, I did try that and it cannot be animated. I'm trying to automate switching between motion blur and no motion blur with RenderStacks, but I would still need to render the whole sequence twice.