HI. I am using poliigon textures.
I was noticing no result in my outcome following the step by step poliigon workflow.
When I isolated both specular and roughness color invert node I could see the inversion was just a plane color.
Is it suppose to work different that photoshop invert ? After inverting my textures in PS I got a perceptible result.
Regards
"... I could see the inversion was just a plane color."
What do you mean by that?
In my testing, it seems that KS and PS yield pretty similar color inversion results.
Dries
Please feel free to see how it behaves in my KS.
First: Poliigon texture
Second: Inver node
Third: PS invert command
It all comes down to gamma and how it is handled in different tools.
The difference between KeyShot and Photoshop arises from the fact that KeyShot applies the inversion on linear (non gamma corrected) color values, while Photoshop likely applies inversion to color managed values (e.g. sRGB).
You can still replicate the conversion result from Photoshop in KeyShot.
The basic process is:
- Remove gamma correction and Interpret the texture as linear color
- Apply the color inversion
- Reapply the default gamma correction
Here's how to do it in the Material Graph:
- In the Textue Map node, set the Contrast to 0 => interpret as linear color
- For Contrast in Texture Map: Gamma = 1 + Contrast
- So Gamma = 1 (linear) if Contrast is 0
- Connect the Texture Map node to a Color Invert node
- Connect the Color Invert node to a Color Adjust node
- In the Color Adjust node, set the Contrast to 2 => apply default gamma correction of 2
- Contrast behaves a bit differently here!
- For Contrast in Color Adjust: Gamma = 0 + Contrast
- So Gamma = 2 (default gamma correction in KeyShot) if Contrast is 2
- Connect the Color Adjust node to a material channel
The inversion result from KeyShot should now be very close to Photoshop.
I hope this helps.
Quote from: DriesV on April 12, 2018, 06:22:38 AM
It all comes down to gamma and how it is handled in different tools.
The difference between KeyShot and Photoshop arises from the fact that KeyShot applies the inversion on linear (non gamma corrected) color values, while Photoshop likely applies inversion to color managed values (e.g. sRGB).
You can still replicate the conversion result from Photoshop in KeyShot.
The basic process is:
- Remove gamma correction and Interpret the texture as linear color
- Apply the color inversion
- Reapply the default gamma correction
Here's how to do it in the Material Graph:
- In the Textue Map node, set the Contrast to 0 => interpret as linear color
- For Contrast in Texture Map: Gamma = 1 + Contrast
- So Gamma = 1 (linear) if Contrast is 0
- Connect the Texture Map node to a Color Invert node
- Connect the Color Invert node to a Color Adjust node
- In the Color Adjust node, set the Contrast to 2 => apply default gamma correction of 2
- Contrast behaves a bit differently here!
- For Contrast in Color Adjust: Gamma = 0 + Contrast
- So Gamma = 2 (default gamma correction in KeyShot) if Contrast is 2
- Connect the Color Adjust node to a material channel
The inversion result from KeyShot should now be very close to Photoshop.
I hope this helps.
Thanks a lot Dries. I very much appreciate this information and the time you took to explain it.
Regards
Thank you so much for this explanation!