Diffuse color pass?

[kirk]

Is it possible to render diffuse/ texture input colors unaffected somehow ? Just plain colors. same exposure level, no ambient occlusion?

[bepeg4d]

hi,
here are some ideas:
- changing the Dl GI settings to Environment
- rendering in Clay Colored mode
- setting the Camera Imager to Linear and Gamma 2.2
- using a low power texture emission node in diffuse material

ciao beppe

[kirk]

Thank you for the reply but I am still getting slightly off values comparing to input textures . I am not sure what 's "low power" means for texture emission node

[bepeg4d]

Hi,
take in mind that Octane Render always work in linear color space.
about the "low power texture emission node", sorry, I had to say "low power efficiency texture emission node". Here is a screenshot of what I mean, basically you have to lower the Value in HSV color space to correctly see the color:

ciao beppe

[kirk]

Should I care at all what space Octane use? Have to convert textures into linear space? Always thought renderers do it automatically knowing input textures are 2,2 gamma

Is there any specific rules how much should I lower the emission value?

[bepeg4d]

Should I care at all what space Octane use? Have to convert textures into linear space? Always thought renderers do it automatically knowing input textures are 2,2 gamma

Yes, you don't need to convert them, here is what roeland says:

In Photoshop you can assign arbitrary color profiles to your image. Octane doesn't support reading color profiles and will always interpret the colors in sRGB (you can only override the gamma value). The save for web option always saves the image as sRGB.

Is there any specific rules how much should I lower the emission value?

Hi, you can use a color correction node to lower the brightness and I forgot to mention that you need to uncheck the "Cast illumination" option. In this way the emission affects only the material itself but does not emit light all around:

constant-diffuse.orbx
ciao beppe

[kirk]

Thanks again, but I am still getting slightly darker values than they are in input .tga texture files . (no vignetting) Tried it with your file too. Wonder if that 0,025 brightness value has some math origin or should I play with it on my own?

[bepeg4d]

Hi,
yes of course, you can play with the value to find out what is better for your needs.
Another option you can use is to activate the "surface brightness", in this way the illumination is no more related with the emitter dimensions. You can play with both the Power and Texture Brightness for fine tuning the effect
ciao beppe