mix strenght problem

[tomschmid]

the mix strength slider in the difuse color chanel doesn't seem to work correctly.
attached a simple test:

mat1
80% white color (RGB 204, 204, 204)

mat2
black color
white image (RGB 255, 255, 255) mix strenght 80%

mat2 is brighter then the mat1
it doesnt matter if i mix the image with VrayLayered-material

i testet this also with vray 3.7 and there the materials look exactly the same like they shoud.
to get the same render results, i have to mix a pure white image with a mix strengt value of 60%.

[aleksandar.kasabov]

Hello tomschmid,

In order to compare the 2 materials, please set the input color profile of the Project Settings (Ctrl+D) to Linear. Once you set the color profile to linear you will get the same results. I hope this is of help.

[tomschmid]

so is it recommended to work always with linear color profile? because it affects the hole image. much brighter.
it also makes the colorpiker a bit strange. a 50% grey doesnt look then like a 50% grey so i think i have to stay in rgb mode.

in vray 3 i've learned that a white paper is not RGB 255,255,255 (100% white) but more something like RGB 204,204,204 (80% white).
so in vray 5 (rgb mode) i have to mix an image with 60% black so the white is not brighter then 204,204,204.

workflow vray 5: 60% mix with black to get 80% white
workflow vray 3: 80% mix with black to geht 80 white

its a bit confusing. was much more logical in vray 3

[deyan.hadzhiev]

Hi tomschmid, the difference observed between V-Ray 3.7 and V-Ray 5 is mostly because in V-Ray 3.7 the document input color setting was considered differently. We changed this behavior in V-Ray 5 to better match the native Cinema 4D material workflow.

Additionally, please check this post, where I have described in details some differences between the classic materials and node materials and is somewhat related as a topic to your query:
https://forums.chaos.com/forum/v-ray...88#post1120088

Particularly in your case, when you have the input color to 80% white, it is converted from sRGB to linear for the render, while using the mix strength the final color is calculated in linear space after the individual colors have been converted from sRGB.