DR - Use Local Host Issue

[joelly3d]

We've noticed that since switching to 3.00.08 a weird rendering issue with Max 2015 happens with Distributed Rendering. It occurs if you use local host with GI (Brute Force and Light Cache). The local host buckets will create GI that doesn't match what the farm is doing. It has happened consistently and across a bunch of different scenes. The solution for us has been to disable local host, which stinks to do because our workstations are quite fast. Has anyone else run into this?
Thanks in advance,
-Joel

[vlado]

If you turn on the option "check for missing assets", do the slaves report any missing textures or anything else?

Also, how do you know that it's the GI that's different? If you compare the various render elements, are there differences only in the GI?

Best regards,
Vlado

[Morne]

Are you by any chance using state sets?

[joelly3d]

I have narrowed down the issue quite a bit and simplified a version of a scene I can share for the VRay team to look at. This has happened to all of us on different scenes, so whatever it is, it is a prominent issue. Here are some notes from my troubleshooting session that may help you guys conclude the problem:

- The local host is the machine that is causing the bad buckets, so "check for missing assets" didn't do anything.
- It works fine when rendering solo or when using the farm, but using both will cause strange artifacts of varying brightness.
- We are not using state sets either.
- Problem still occurs even if the materials are stripped down to a single node
- It definitely seems like it is also related to lighting. Only certain nooks "qualify" for the bug to be visible, not sure why or how.
- I have not been able to recreate the issue when making new assets in the new build. This could indicate that it has to do with older assets being migrated to the new build.
- The problem shows up in the GI but is even more prominent in the rawreflection pass, it seems the reflectivity is a likely candidate.


here's a view of the issue on a simple material that has reflectivity:


I'd love to know what you find out is the cause. Also, let me know where to drop or email this scene so you guys can have a look.

[vlado]

Do you think you can get us a scene for that to support@chaosgroup.com ?

Best regards,
Vlado

[joelly3d]

Sent!
The email is titled "Local Host Scene Issue".

[rotab4d]

Hello .. any luck with that problem ?
I am having similar problem .. I am pretty sure it's not texture or network related issue since the textures shows up ... it's just that the render slaves renders brighter buckets than the main machine .. Also it's not GI related .. i have disabled GI .
may be it's gamma issue ( my scene max's gamma is set to 2.2 and using reinhard 1 , 0.75 ) ...
The main machine uses dual xeon E5-2687W while the slaves are Ivy Bridge i7-4770 ..
Regards ,

[rotab4d]

Quick Update ,
I have tried everything said in the varied bucket brightness problem in previous threads on this forum ,, and nothing helped ..
But i thought i might disable Max's Gamma and Lut ..... and it worked .. now i am getting even brightness on all buckets from my main workstation and the renderslaves ..
Btw i had this problem before with vray 2.XX

[jacksc02]

as you say it is a gamma issue.
The slave buckets return an incorrectly gamma'd GI prepass but it is only a display problem and it doesnt affect the GI.

[joelly3d]

After re-install, I have set the gamma properly on all of the machines and it behaves correctly. However, I literally had to open the scene on the farm machine and set the setting inside max for them to take appropriately. Copying the settings ini didn't work as expected. I still think this is a silly issue, shouldn't max inherit the gamma settings of the file it is about to render?

Also, it could have been remnants of previous max versions on the machine. I don't know how they would interfere, but i removed all previous versions and components like backburner and re-installed from scratch. All is functioning fine now.

Some of the machines that are a bit older required a full uninstall of all autodesk products, then a re-install of max and vray from scratch. Pain.