EXR Output with Network Rendering

[Mkbart]

Hello, I'm trying to come up with a workflow for rendering animation and outputting EXR files.
During this task I came across multiple problems, I'm not sure whether they're on Max or Corona end.

My requirements are simple: 16-bit for most of the render elements, 32-bit for Velocity, WorldPosition, ZDetph and UVWCoordinates.

However, it turns out, it's almost impossible to get this setup when rendering either with Pulze or Deadline. When rendering locally, it's great - I'm using Manual "Add" Render Elements dialog inside EXR save options. I can add manually all passes and choose their bit-depth separately. When rendered locally I get Multilayer EXRs that meet my requirements above. However, as soon as I try submitting to ANY network solution, passes don't get saved - I end up with Beauty only.
I thought, maybe setting the depth-bit to 32 and checking "Automatically add render elements" checkbox could help, and it does - passes are included in the EXR but suprise! All of them are forced into 16-bit, even if main setting is set to 32.

So my only option for network rendering is to produce separate EXR files for each pass and in 32-bit depth, which bloats the disk space a lot. Is there really no other way? Looking for some suggestions, thanks in advance!

[Frood]

Hi,

I was pretty sure that no one will answer to this, so I will do. It's a 3ds Max design flaw when it comes to network rendering because the EXR settings are stored locally, they do not get part of the scene (same applies to other output formats btw.). The relevant file is 'fOpenEXR.cfg' in the plugcfg directory in this case.

My personal solution is to always use "Automatically Add/Remove Render Elements [...]" when setting up the output and having a script as (one of the) prerender scripts that sets AutoAddRenderelements to 'true' on every node when the render job starts. It would not help you if adding the elements manually (and defining different output formats (16/32bit accuracy) though, but you get the point. Also see

https://forum.corona-renderer.com/index.php?topic=25686.0

This and other issues can either be solved by Autodesk (well...unlikely) by storing the output file settings in the scene, or by Chaos if implementing their own output system for Corona. Currently it uses the output system of 3ds Max.


Good Luck

[Mkbart]

Hi,

Thanks a lot for a great (and pessimistic) answer!

Looking at your thread link, the issues were already there 6 years ago - that doesn't give me much hope for them being fixed either in Max or in Corona.
Funny thing - over 50% of our trouble using Corona would disappear if it stopped relying on Max file output. It’s been a consistent pain: render elements paths not being updated, PNG output error messages, and now this.
Makes me wonder - all these industry standard render elements are there: Velocity, WorldPosition, they even added Cryptomatte - only to be crippled by weird CXR-only methods, flawed output, etc.

Seems we have to investigate and simply move to V-Ray or other solutions.

Thanks again.

[TomG]

Their are related ideas on the Ideas Portal (https://chaoscorona.ideas.aha.io/ ) where one solution could be writing our own save routines (mostly things to do with EXR or network rendering, and applies under C4D as much as Max), but you could start an explicit one that is for the writing of our save routines and removing reliance on the DCC. This is something on my mind already, perhaps for 14 later this year, so user votes could help indicate how many would like to see such a thing which could play into the prioritization of what is quite a bit of work. Thanks!

[Mkbart]

Thanks, Tom, I added the idea here: https://chaoscorona.ideas.aha.io/ideas/CMAX-I-170
It would be amazing to get that, because we do love using Corona, but seems like this limitation affects so many of its features.

[TomG]

Thanks for taking the time to add that! I will make it live shortly so folks can vote :) Understood on the frustrations that come with it, have run into them myself at times lol :) Definitely been a growing concern of mine over the last year or so even more than usual. Plans for 14 will be made in June once we are at the point of release 13, so plenty of time for people to vote on this if they too are running into problems.