Attempting to export VRScene file crashes 3dsMax

[miguel_sousa]

We have an automation script that exports 3dsMax scenes in batch as VR scene files, which are them submitted to Chaos Cloud for rendering. One specific scene is causing the exporter to crash 3dsMax as a whole as soon as the vrayExportVRScene command is executed. No useful information is encountered in the 3dsMax or the VRay log files, nor is any exception produced before the application crashes.

From testing, this doesn't seem to be an issue with our script, as it happens with the UI as well. Some findings we collected so far:

• I can reproduce the issue both through script and the UI, with 3dsMax 2022 and VRay 5, as well as 3dsMax 2023 and the most recent version of VRay 6.
• Resetting 3dsMax settings to factory didn't change anything, nor did resetting the VRay render settings (by changing to a different renderer and then back to VRay).
• This seems to be something related to the specific geometry we have in the scene:
  • The issue is not reproducible with other scenes or models. If I add a sphere to the same scene and export just the selected sphere, it works fine, too.
  • The issue is reproducible if I merge the 3dsMax scene in question with a blank scene.
  • When selecting node by node and exporting by selection, only a few of the nodes seem to cause the issue.
  • The problem seems to go away when triangulating the model with a Turn to Poly modifier before exporting the scene file. Previously, the model was already an Editable Poly with Quad faces.
  • All nodes that were causing the issue had an OpenSubDiv modifier. Collapsing the stack of modifiers doesn't seem to have changed anything.
• The issue happened both when exporting with and without settings, in multiple path locations, with different file and node names.

The scene file in question was made by a client of ours, but if needed for debugging I was allowed to share it privately.
While triangulating the model is a quick and easy solution, we would like to understand what exactly caused the application from crashing to prevent it from happening in production and, if needed, add proper checks and/or change the workflow.

Thanks in advance!

[yavor.rubenov]

Hello,

It would be best if you can submit the scene to our support.

Best regards,
Yavor