Chaos Corona Forum

Chaos Corona for Cinema 4D => [C4D] I need help! => Topic started by: Nube architetture on 2019-06-26, 13:26:45

Title: HDRI Gamma problem
Post by: Nube architetture on 2019-06-26, 13:26:45
hey everybody, how are you ?

I have a little problem

I can't use properly peter guthrie skies.
Usually i use a corona light material with an Hdri map, in the same panel i change the exposure of the map to -4.3. Then i apply a filter to correct the gamma to 1 to 0.75 (Just for boost the shadows)  but the result is very ugly. The problem is the oversaturated colors, the sky is too cyan. 

could  anyone help me ?

What is the right way ? Are there any tutorials that could help me ?

I prefer don't use the combination with hdri and corona sun, i'm looking for a method to change the gamma but not the color.

Thanks guys
Title: Re: HDRI Gamma problem
Post by: burnin on 2019-06-26, 14:11:27
You can use Cinema's Filter Shader (https://help.maxon.net/us/#XSLAFILTER-ID_SHADERPROPERTIES) on any HDRI, texture, ... within Corona Materials.
Title: Re: HDRI Gamma problem
Post by: Nube architetture on 2019-06-26, 21:40:44
i've tried to render the same image on 3ds and c4d.
With the same parameters, same HDRI, same exposure and gamma.

The c4d image has more cyan and blu in the shadow and the sky is oversaturated and more close the cyan, the image looks unnatural.

The 3ds version has a very soft shadings in the sky more close to the blu, the light looks more naturale and i like it.

Both images has the same parameters. Both used a bitmap with a corona color correction, c4d image has a c4d filter to change the gamma (this is the only difference) .

Anyone knows how can i reach the same result on c4d ?

I don't know if it is the right section to post something like that.

thanks bye
Title: Re: HDRI Gamma problem
Post by: burnin on 2019-06-26, 22:28:12
from the looks it feels like you're not working the same linear workflow - something's a miss
Title: Re: HDRI Gamma problem
Post by: Nube architetture on 2019-06-27, 10:28:37
This is the informations that i found

C4d has the tick on the linear workflow option.


Title: Re: HDRI Gamma problem
Post by: Nejc Kilar on 2019-06-27, 11:50:37
Interesting stuff... Have you perhaps try double checking if the bitmap is imported with a linear profile? Also, is there a huge difference with the "filter" being applied or just the bitmap on its own?
Title: Re: HDRI Gamma problem
Post by: Nube architetture on 2019-06-27, 12:26:08
This is the material that i have applied to the sky
Title: Re: HDRI Gamma problem
Post by: Nube architetture on 2019-07-01, 17:57:28
hey guys
One week after same problem
could anyone help me ?
I'm really struggle with it  :(

thanks Bye
Title: Re: HDRI Gamma problem
Post by: Ales on 2019-07-01, 20:57:55
Hi,

to summarize, in 3ds Max you have bitmap with input gamma set to 0.76, this bitmap is then modified via color correct (reducing exposure) and used for environment and you want to recreate this setup in C4D? In that case there are two things you need to change:


Apart from these, you might also want to check you use the same tone mapping settings in both 3ds and C4D.