[OPEN] [VC4D-2013] Velocity Pass Rendering Strange Shapes

[jeffrey_krigstein]

Hi all,

I'm rendering a velocity pass on some basic moving geometry and it's creating really strange results. See the screenshots below. Can anyone advise me on what's causing this?



The visual errors remind me of z-fighting, but the geometry doesn't appear to have any overlapping polygons. The errors also appear in different places each time you render the same frame. The two images above are the same frame rendered twice without any changes.

The geometry itself is created with a Tube object inside a Cloner with a Random effector applied. Attributes of the tube are animated over time to change its shape.



The Velocity render element is set with Clamping off.



A copy of the C4D scene is attached as well.

Thanks for any assistance!

Jeff

[zhanet.georgieva]

Hi jeffrey_krigstein,

It appears that the strange rendering output occurs when animated height changes are applied to the primitive objects (the tubes in your scene). This problem occurs only when rending with GPU RTX mode and this is escalated to our Dev team for further investigation (VC4D-2013).

In the meantime, as a workaround you can switch to GPU CUDA mode if you prefer to render with V-Ray GPU or to render your scene with CPU.

[jeffrey_krigstein]

Thank you so much for the workaround zhanet.georgieva! I really appreciate the quick support.

(Thanks for flagging it with the dev team also.)