Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] Bug Reporting => [Max] Resolved Bugs => Topic started by: alexyork on 2016-02-26, 10:18:06

Title: Render Autosave EXR Bug - Wrong White Balance & EXR Format
Post by: alexyork on 2016-02-26, 10:18:06
Hi folks,

I think I found a bug here, or maybe two related ones.

I have set my main Save File output to Half Float (16bits/channel) EXR in the Common Tab, with zip compression per scanline band, Store Image as Tiles, Save Full Image. When I enable render output autosave in System Tab, any autosaved renders are coming out enormous file size (350mb instead of the proper file which is only 90mb), even though they are the same resolution (6k). So I assume that the autosave renders are not in fact respecting the settings from the Common Tab.

Furthermore, the autosave EXRs have an incorrect white balance compared to the final proper file. They are considerably warmer. Even the _end001.exr file is incorrect compared to the final proper file.

I am guessing there is an inconsistency between the autosave EXR settings and the Common Tab Save File EXR settings.

Cheers,
Title: Re: Render Autosave EXR Bug - Wrong White Balance & EXR Format
Post by: pokoy on 2016-02-26, 10:43:50
I believe the auto-saves are saving additional data (the also always default to exr to save additional channels for that reason) so you can continue rendering at a later point. That would explain why they don't respect any tone mapping user settings and always save a raw render.
Title: Re: Render Autosave EXR Bug - Wrong White Balance & EXR Format
Post by: alexyork on 2016-02-26, 12:22:22
I thought that might be the case, but the file is still 6k and I though the Corona EXR (the raw one) was double resolution?

Either way I'm not sure if this is the ideal behaviour. I wonder if it would be possible to have Corona save out both a raw version which can be resumed *and* a "proper" version with user tonemapping applied, so you can simply use file directly in post. I guess the workaround is to load the file and "resume" it, then immediately cancel and save it out. Seems a bit cumbersome...
Title: Re: Render Autosave EXR Bug - Wrong White Balance & EXR Format
Post by: maru on 2016-02-26, 13:25:58
The EXR saved from autosave is in fact a special Corona EXR. You can read about it here: https://coronarenderer.freshdesk.com/solution/articles/5000501975-corona-exr-format

I agree that it would be convenient to have at least the possibility to load a Corona EXR file from autosave to Corona VFB directly without the need to have the rendering continue.
Title: Re: Render Autosave EXR Bug - Wrong White Balance & EXR Format
Post by: alexyork on 2016-02-26, 14:20:02
Thanks Maru, that's what I figured. We can load and resume one of the autosaved renders, cancel it and then re-save, which works fine. It's a little cumbersome though. It would be great it it saved out 2 renders each time - one raw and one tonemapped.
Title: Re: Render Autosave EXR Bug - Wrong White Balance & EXR Format
Post by: PROH on 2016-02-26, 17:12:43
+1 for the option to save one raw and one tone mapped render. This would definitely be an easier and more flexible workflow.
Title: Re: Render Autosave EXR Bug - Wrong White Balance & EXR Format
Post by: Ondra on 2016-05-02, 15:07:01
Fixed by creating 2 files for each autosave - colormapped and raw
Title: Re: Render Autosave EXR Bug - Wrong White Balance & EXR Format
Post by: alexyork on 2016-05-02, 16:30:24
Brilliant! Thanks chaps :)