xgen hair render issues when rendering with vray velocity pass

[cum. m+d]

hey guys,

I'm doing an animation project now which involves using xgen hair for our character.

I'm facing some issues while rendering the velocity pass for my animated character as I didn't get any velocity information of the "xgen" hair in the render pass.
The character was previously referenced in to the scene to be animated, but I've already imported the character reference.

here are my xgen settings in maya, I've made sure to export patches for animation (alembic), set my renderer to vray and tick "require alembic file with exported patches for animation" for all descriptions.



I'm pretty new to xgen, I'm not sure if there's anything that I've did wrongly.
Has any of you guys had encountered the same issue or might know where the problem lies? Any help would be greatly appreciated.

Im using maya 2018.2, vray 3.60.03

[shaio]

Hi,
we did have some issues with V-Ray 3.60.03 related to the xgen and velocity that we fixed. Could you please download and check the latest stable release 3.60.05 and let us know if you're still having issues with the velocity render element.

[cum. m+d]

Hey Ivan!

I see! Thanks for the update. I'll try again with the latest vray version. will keep you guys posted.

[trainofthought]

This still seems to be happening to me in Vray 6 GPU RTX on Maya 2022.5. Though I am using a spline cache, but have no other option. Is there a fix yet?

EDIT: I've just checked and this works fine on Vray CPU. Yet another limitation of rendering on GPU - at this stage I've found dozens of such limitations during the course of a single project, perhaps I should come and work for Chaos?!

[hermit.crab]

Thank you for the feedback. The issue is reproducible. I've logged it (internal bug-tracker id: VGPU-6326) for dev investigation.

[trainofthought]

*BUMP* This error is still not fixed as per Vray 6.2 - can we please prioritise this as it's causing me to have to do two renders (one GPU and CPU) for every single scene just to get a velocity pass out with my Xgen fur. Very frustrating and time consuming!