Maya 2025.1 + V-Ray 6.20.03 -> Volume Grid render issue

[seq]

Hi,

for a snow effect we have exported sequence of vdb files from Bitfrost and load them via VRayVolumeGrid-Node. The sequence is 130 frames long. The timeline origin is set to 1000.

The snow renders fine until frame 1071. On frame 1072 and afterwards it is still visible in the VP, but it doesn't render anymore. The vdb file fro frame 71 and 72 has nearly the same size and when rendering frame 1072 the vdb file is loaded successfully:

[2024/Oct/18|12:39:05] V-Ray: [PhoenixCachePlugin] Frame data 72000 successfully loaded from X:\maya\projects\placeholder\cache\produkt_06b_241 015_01\Schnee\produkt_06b_241015_01_VDB_####.vdb.
[2024/Oct/18|12:39:05] V-Ray: [PhoenixSimPlugin] grid -1586 -294 -3181 - 2474 784 2652, cache index -2147483648.

But there is no snow anymore in the rendered image?

Any tips+tricks?

TIA
Lars

[vladimir_krastev]

Hi, thanks for posting. Are you able to render the snow if you start the animation from frame 1071? Are you able to render the snow if you render the frames above 1071 as single frames (try a few and let us know how it goes)?
Could you send us the scene and vdb files or at least the vdb files for a test? Please do that here or through the support contact form.

[seq]

Hi Vladimir,

thanks for your reply.

We tried to render several single frames above 1072, but all are black. Shifting the animation to 1071 as starting point, doesn't help.Then the snow is visible until frame 1142 and disappears afterwards.

We can send you the files, but as the vdb files are 40 GB in total, we would send you only the vdb files for frame 70 - 75. The zip is still 1,85 GB big. Can we upload that?

Best
Lars

[seq]

Just send you the sene file and five vdb files via support contact form.

[vladimir_krastev]

Thanks, I have the ticket now. We will look into the issue and get back to you.

[seq]

Perfect. Thanks a lot for the support!