Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: SameerGore on 2016-06-08, 14:56:14

Title: Gamma Issue
Post by: SameerGore on 2016-06-08, 14:56:14
Hi coroners,
I've just started using CORONA and still in R&D phase.
While corona dosen't have save rendered image option in render settings like Vray (if I'm not wrong), I'm using 3ds Max native render save option with all render elements. but images saved with this option are carrying Gamma 1.0 whereas I've set all parameters to 2.2.

Please help me with this or suggest if there is another option for saving renders.

Thanks.
Title: Re: Gamma Issue
Post by: TomG on 2016-06-08, 15:21:29
Not sure what you mean by "3ds Max native render save option" - thinking you may mean save from within the Max VFB?

Anyway, if you save from the Corona VFB (or click and hold Save to open up the Save All if saving multiple passes at once) you will should be getting the expected results (see image attached of the Corona VFB toolbar) and same if saving from a "Save File" setting in the Render Output section in the Common tag under Render Setup dialog.



I did find in Fusion 8 on loading an EXR saved from Corona I had to reapply Gamma 2.2 (in a Brightness / Contrast node) to get the same results as the render, though Photoshop displayed it as expected, but I am no Fusion expert so may have just had a wrong setting on the Loader node :) Just in case it is the application you are opening it in that is making a difference, too.
Title: Re: Gamma Issue
Post by: maru on 2016-06-08, 16:14:19
Tom, AFAIK gamma is not saved into 32-bit EXR, so if PS opens it with the same gamma as in VFB for you, it probably means that it automatically converts it to sRGB.

I am also not sure what OP means. Please check if all your gamma settings are correct: https://coronarenderer.freshdesk.com/support/solutions/articles/5000515647
Title: Re: Gamma Issue
Post by: TomG on 2016-06-08, 16:23:08
Ah that naughty Photoshop! I've never installed any of the EXR handling plugins for it as only just started with EXRs for testing in Fusion, but thought I'd see what Photoshop did to it on open for this thread- sneaky of it to do some conversion without telling me, tsk. I ought to add that in this instance it was a half float 16 bit EXR, as I got those working as expected in Fusion, just in case it is relevant to what the OP is doing.
Title: Re: Gamma Issue
Post by: mraw on 2016-06-08, 16:43:02
AFAIK you have to tell Fusion what to display. I would use the Gamut LUT(small Icon in the viewport) in your case. Press 'Edit' and then 'output space' srgb.
Or if you prefer a node, I'd use a gamut node instead of the Brightness/Contrast.
Title: Re: Gamma Issue
Post by: TomG on 2016-06-08, 17:14:10
That works much better, ty! I went with the Gamut node solution. Also I seem to be having no trouble with a 32 bit EXR in Fusion today, not sure what I did to break it yesterday.
Title: Re: Gamma Issue
Post by: SameerGore on 2016-06-08, 18:05:48
and same if saving from a "Save File" setting in the Render Output section in the Common tag under Render Setup dialog.


Thanks TomG,
I've used this method as I was submitting job to BB.

This time in save dialog I put override gamma value to 2.2 and it worked

(http://i.imgur.com/iWJzyGJ.jpg)


I was looking for the save option similar to Vray
(http://i.imgur.com/LdWvjhK.jpg)

Anyways now I know what to do

Thanks guyz.