render finishes with incomplete areas and/or freezes at 99%

[peterbrobie]

I'm experiencing two issues repeatedly in various files, each of which uses the same components or proxies from my library.

1. The progress window states that the render is 100% finished, but in the VFB, there are one or more buckets that are either left totally black or look half complete and fuzzy.

2. The progress window gets to 99% complete, and the VFB appears to be about 99% complete, but the render never actually finishes. I've waited up to 1.5hrs for completion of a render in which the previous 99% took only 15-20 mins, but the final 1% is never completed.

The issue seems like it may be related to reflections or particular materials. I'm experiencing the same Laubwerk issue noted by Mousa_SA in another topic, and often the incomplete or hanging renders are on Laubwerk foliage. Incomplete areas also frequently occur (about 75% of the time) on the rear taillight of a particular vehicle model that I use.

The attached screen shot illustrates the problem.

[Peter.Chaushev]

Hello,

Could you please send an email to support@chaosgroup.com with further info about this issue as well as the one where incomplete areas occur?
What version of V-Ray you are using? Does the issue occur only in this specific project?
Are any other 3rd party plugins used (beside V-Ray and Laubwerk)?
A copy of the complete progress log until the moment the renderer hangs as well as the archived scene (Extensions > V-Ray > Export > Pack Project) would be certainly ease the investigation!

Kind regards,
Peter

[peterbrobie]

Thank you for your reply, Peter. I will pack the project and send the email as requested.

I'm using VRay 3.4.04. The issue is not specific to this project. However there is at least one model that I know of that triggers this behavior. The black Honda CRV that you see in the foreground, right side, usually triggers an incomplete area on the red portion of the taillight. I have since upgraded that material from a 2.0 vismat to a 3.4 vrmat, and that issue didn't occur with this render, but obviously did in other unexpected areas. The only other 3rd party plug-in that I have working at render time is Skatter, for the grassy areas.

Best,
Pete

[peterbrobie]

just as a follow up for anyone following this thread:

in experimenting further, it appears the cause of splotches/unfinished rendering is old vray materials (non-brdf). specifically materials with reflectivity. i have gone through some models and updated all of the highly reflective materials to the new shader type, and the renders have far fewer errors.

that said, I typically have 100s of materials in a model, and many proxies with 10s or 100s of materials that use old materials. updating every single one is going to be really laborious if i ever actually get to it. is there anyway to automatically detect and update older materials?

thanks,
pete

[Peter.Chaushev]

The upcoming v3.6 update will include a material migration script which should take care of any discrepancies between render outputs from v2 and v3. I just rerendered the scene you initially submitted using our latest internal builds and found no issues.
In case of possible material gamma discrepancies, the "Linear workflow" checkbox will still be there to provide compatibility.

Kind regards,
Peter