Issues with Karma renderer using OpenColorIO

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I have OpenColorIO installed and it displays successfully in the view, this is what I see in the view.


However, the image output using Karma is the original color (not colorized by OpenColorIO).



Here is my Karma setup.


Have you ever encountered such a problem? How did you solve it?

thank you very much for your help.
Edited by HenDaSheng - Sept. 13, 2022 07:30:44
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I ran into that problem as well. Try setting your Output space to data and your input space to srgb_texture, then render to disk. Also, set the color space on the texture node to srgb_texture as well. Then, in the viewport disable all color correction, or verify your image using a non-houdini tool like Photoshop.
Edited by Enivob - Sept. 13, 2022 08:27:26
Using Houdini Indie 20.0
Ubuntu 64GB Ryzen 16 core.
nVidia 3050RTX 8BG RAM.
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I'm not 100% but I don't know if "aces" is an acceptable output space. Wouldn't it need to be ACEScg or ACES2065-1 or something like that. Use the menu on the right of the Output space field to see the available color spaces.

ACEScg has been working with Karma on my end.
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HenDaSheng
I have OpenColorIO installed and it displays successfully in the view, this is what I see in the view.


However, the image output using Karma is the original color (not colorized by OpenColorIO).



Here is my Karma setup.


Have you ever encountered such a problem? How did you solve it?

thank you very much for your help.

The output will already be acescg, you don't need to d anything to convert. Including 'data' as either the from or to colorspace will result in no transform. The colorspace named data refers to non color data that should not be transformed.

If you're trying to bake the image down to a display space image, eg a jpg or png, then you will need to apply a post process color conversion with hoiiotool or some other software. It can also be done with COPS if the output display transform is also defined as a colorspace. (They are not typically)
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If you are using OCIO, you do want to use data to preserve brand/original texture colors. The proof is in the render. This image shows the original particle sprite textures supplied to Houdini along the bottom. In the upper left, you see the frame rendered with data/srgb_texture. On the upper right, you see the output space set to aces. There is a color transformation taking place. All the other output spaces also mangle the colors.


Another solution is to click the clear button and not transform the color space at all. Beware, however, this doesn't disable color space mangling in mplay, which adds to the confusion. Decide where you want your color space to be correct and match to that app. Some apps read these value differently. Using data is like unity gain on your guitar pedal, no distortion.
Edited by Enivob - Sept. 13, 2022 19:42:05

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Using Houdini Indie 20.0
Ubuntu 64GB Ryzen 16 core.
nVidia 3050RTX 8BG RAM.
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I'm not 100% but I don't know if "aces" is an acceptable output space. Wouldn't it need to be ACEScg or ACES2065-1 or something like that. Use the menu on the right of the Output space field to see the available color spaces.

ACEScg has been working with Karma on my end.

Thanks, the options on the right side of the output space field still don't work on the output image, is there anything else that needs to be set?
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Enivob
I ran into that problem as well. Try setting your Output space to data and your input space to srgb_texture, then render to disk. Also, set the color space on the texture node to srgb_texture as well. Then, in the viewport disable all color correction, or verify your image using a non-houdini tool like Photoshop.

Thank you for your help, but I still can't solve it, I will continue to think of a way.
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