Serious Bug regarding Colors -- Vray 5.20.05 / Update 2.5

[index]

1.) Create 2 default Vray-5 Materials
2.) in Material A diffuse add a Color Shader with RGB 128,128,128, Brightness 100%
3.) in Material B diffuse add a Color Shader with RGB 255,255,25, Brightness 50%

--> they should look the same, but do not

seems to be a general thing with Color Shaders (it happens inside Layer Shaders as well)
Brightness is not ignored but something is off ... maybe Gamma applied ?

RGB 255,255,25, Brightness 21% looks approx. the same as RGB 128,128,128, Brightness 100%

[aleksandar.kasabov]

Hello index,

This has already been discussed in this thread. The difference is caused by the different color spaces in that the colors are calculated. Set the Input Color Profile of your project in Linear and you will get the identical results. Please check the thread for more details. I hope this is of help.

[index]

jeez... thanks for clarifying... I need to check out what this means regarding to file conversions...

still.. doing some tests I get very strange results .. i will post them in the other thread

[index]

Really sorry, but I did a lot of tests and i think there is an issue regarding brightness... i will post that in the other thread later.

Aside of that I just found another issue regarding color shader brightness which is very easy to test :

1) create a c4d material and a v-ray 5 material

2) in diffuse add a c4d layer shader with this setup
- top : color white - multply
- bottom : color (RGB 255,255,255 w brightness 50%) - normal

3)
correct / c4d behaviour —> 50% grey
vray 5 behaviour —> white --> the brightness is completely ignored

[YunalZobu]

- bottom : color (RGB 255,255,255 w brightness 50%) - normal

Hi index,
just out of curiosity, what's the reason of simply not using a RGB of 128 for that same grey shade?

If you take a look at the attached screenshot, I think I might have a solution for you to test

[index]

YunalZobu
hi yunal, yes i know that ofc
you can work with RGB 128,128,128 w brightness 100%
but it is still a bug that needs to be fixed

i mean with a flat tire you and sirio would probably say, hey no problem, i just go hollywood and drive at angle on 2 wheels
but for normal people fixing the tire makes life much more relaxed for driving .-) (haha.. peace)

but seriously... atm it is very wise not to use color brightness at all in vray-5

i hope these reports are welcome... the intent is to improve things

[YunalZobu]

I was just curious of your use-case, that's all
What about the setup I suggested, do you think it might work for you?

[index]

this was just a setup to clearly show the effect

the usage case is just any layer shader setup with colors...
i mean vray 5 doesn't have the mixmode in color/texture inputs
so you need more layer shaders