Cryptomatte and AOV questions

[remKa]

Hello,

I was wondering why I can't see different colors in the cryptomatte material node or in the cryptomatte geometry node name in the viewport ? Every objects (which have direfferent materials ) appears green

It seems to work in the c4d plugin (please see attached file).


My second question is : could I use AOV system to get the alpha of objects behind a glass of water, meaning that I could have the alpha with the refraction's deformation ?

If yes, how can I achieve that ?

Thank you in advance !

[neonZorglub]

Hello,

I was wondering why I can't see different colors in the cryptomatte material node or in the cryptomatte geometry node name in the viewport ? Every objects (which have direfferent materials ) appears green

It seems to work in the c4d plugin (please see attached file).


My second question is : could I use AOV system to get the alpha of objects behind a glass of water, meaning that I could have the alpha with the refraction's deformation ?

If yes, how can I achieve that ?

Thank you in advance !

Hi remKa,

For the 'green' vs 'colored' cryptomatte passes, the main option is in Render settings / Kernel / Special Passes setup.
The Render False Color has True, False and Auto.
Because the False colors used to be only available in LDR mode, the Auto mode enable the False Color only if the LDR mode is set, and disabled in HRD.
Note that for further editing of a exr file with other software that support crypromatte, False color should be disabled, and the Render Tone mapping mode should be HRD.

The False color mode ise used to clearly visualize the mattes.

For the alpha, I'm not sure what you want to archive..
You could start with an AOV output with 2 layers:
Layer 1 : a Render AOV with the Opacity pass (Render AOV)
Layer 2 : a Mask with Cryptomatte, with 'Material node name' type, and select the material of your transparent object.

But what's behind the glass won't be selected, as the glass material will be on top..
You could use a different layer ID for the glass, and render without this layer..

Thanks

[remKa]

Hello NeonZorglub,

Thank you for the explanations