Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: Goldrakes73 on 2020-04-14, 02:02:31

Title: Saturation problems in post viewport
Post by: Goldrakes73 on 2020-04-14, 02:02:31
As in attachment, when I add just a little saturation there are problems in color. The background is a place with just a gray color from Corona. All light are white and nothing pink in scene! what happen?
And also without add saturation the image appair so low in saturation...
I use last Corona

Corona version: 5 (Hotfix 1)
Defines: Wide RGB
Title: Re: Saturation problems in post viewport
Post by: Juraj on 2020-04-14, 10:42:54
The values in Tonemapping are on almost random scale. Saturation is the strangest and has extremely sensitive value.

Outside of that, it also affects tone value too much (it makes the color much more darker or lighter).

I highly recommend to not use it at all. Use "Vibrance" in any post-production software.

Title: Re: Saturation problems in post viewport
Post by: Goldrakes73 on 2020-04-14, 15:23:41
Thank you Juraj! I understand! Yes it's true, I see that Tonemapping is extremaly sentitive..
I notice it now because I dont remember on previous versions of Corona have seen such problems on the color... I will try to reinstall previous versions to verifiy it.
Title: Re: Saturation problems in post viewport
Post by: maru on 2020-04-14, 16:15:48
What color is that "gray" background? Right-click in the VFB to sample the color values.
Title: Re: Saturation problems in post viewport
Post by: Goldrakes73 on 2020-04-14, 17:00:05
Maru...is not a background but is a plane with a material that changes color if I increase value in the saturation on Tonemapping
Title: Re: Saturation problems in post viewport
Post by: maru on 2020-04-14, 17:26:22
Maru...is not a background but is a plane with a material that changes color if I increase value in the saturation on Tonemapping
Ok, great, thanks for the explanation. But can you please render this in the VFB with default saturation, right click on any of those gray pixels, and check their RGB values? (right-clicking should up a color picker with various information printed in it)
I am asking, because some time ago a similar issue was fixed, so this is definitely not expected.
Title: Re: Saturation problems in post viewport
Post by: Goldrakes73 on 2020-04-14, 17:42:07
Yes! as you can see in my attachment, I rendered a frame with a default value in the saturation, and all is ok, but the problem happen when I increase the saturation and the grey color change in pink this is strange...
Title: Re: Saturation problems in post viewport
Post by: TomG on 2020-04-14, 17:45:13
However, rather than just the screen grab here, we really would like to know the RGB values of one of those grey pixels in the VFB, to see if they are truly grey, or if there is a slight color tint to them. If you could do as Marcin suggests, and right click in the VFB to bring up the pixel information, and screen grab that, it would be a big help. Thanks!
Title: Re: Saturation problems in post viewport
Post by: maru on 2020-04-14, 17:51:29
The idea is to see if the color is really neutral (e.g. RGB 100) or if one of the values is higher (e.g. R 101 G 100 B 100)
Thanks!
Title: Re: Saturation problems in post viewport
Post by: Goldrakes73 on 2020-04-14, 20:18:21
in attachment
Title: Re: Saturation problems in post viewport
Post by: Frood on 2020-04-16, 10:15:32
Btw: CoronaColorCorrect acts in the same, unexpected way. I stopped using it entirely.


Good Luck



Title: Re: Saturation problems in post viewport
Post by: aaouviz on 2020-04-16, 10:54:58
Btw: CoronaColorCorrect acts in the same, unexpected way. I stopped using it entirely.


Good Luck

Interesting. What do you use in place of it?
Title: Re: Saturation problems in post viewport
Post by: Frood on 2020-04-16, 11:42:34
What do you use in place of it?

Standard Max Color Correction (in "advanced" mode) or just options in the Output rollout of bitmap nodes and standalone Output map (color map preferably). We abandoned "Color Correct" (https://cuneytozdas.com/3ds-max-plugins/) some time ago after decades because I thought we would not need it any more - maybe I was wrong :)


Good Luck


Title: Re: Saturation problems in post viewport
Post by: maru on 2020-04-16, 12:03:02
in attachment

Ok, so the tone-mapped values are:
R: 208
G: 206
B: 207
That's why this color becomes pinkish/reddish when saturated. The question is: why are they like this if the original values are identical. Maybe it's environment lighting, direct light, indirect light, or color temperature?