Octane for Blender cryptomattes not creating layers in Photoshop

[Longbongosolo]

I am using Octane for Blender to generate cryptomatte passes. I save the rendered file as multilayer EXR and then open it in Photoshop using the EXR-IO plugin but it is not splitting the cryptomatte into separate layers. I use the same workflow with renders from Octane for Modo and the cryptomatte splits as expected. The only difference I can see is that the Blender EXR file has a layer group called ViewLayer which contains all the output layers. Not sure if that could affect the way cryptomatte passes are interpreted by the plugin? Any thoughts?

I've attached a screengrab of how the Blender EXR file opens in Photoshop...

[linograndiotoy]

Hi,
I've never used Cryptomattes in Photoshop.
Can you please show me what the expected result should look like once the EXR is loaded in PS?

[Longbongosolo]

Hi,
I've never used Cryptomattes in Photoshop.
Can you please show me what the expected result should look like once the EXR is loaded in PS?

Yes, here's two screengrabs of EXR files opened in Photoshop using the Exr-IO plugin. The first is rendered with Modo Octane and is correctly splitting the Cryptomatte layer into separate layers for each material. The second is rendered with Blender Octane. The Cryptomatte is there as a layer but it is not splitting into separate material layers when opened.

[Longbongosolo]

Also, I have asked on the Exr-IO Discord where it was recommended that I follow the workflow as described in the video https://www.youtube.com/watch?v=43TRMeQZlzA and the Add-on script at https://www.exr-io.com/automate-blender-exr-elements/

[Longbongosolo]

This seems to be an Octane specific problem because I tried rendering the same scene with EEVEE in Blender and it all worked correctly.

[linograndiotoy]

I’m wondering if the issue might be related to how the CryptoMatte pass is labeled in the EXR file.
If you open the EXR saved from Octane for MODO—without using the Cryptomatte plugin in Photoshop—what’s the exact name of the layer shown?
It could help determine if the problem is due to inconsistent layer naming across integrations.

[Longbongosolo]

I'm attaching screengrabs of how the Modo Octane EXR opens in Photoshop vs how the Blender Octane EXR opens in Photoshop, both using the ProEXR plugin (no cryptomatte layer support) and the Exr-IO plugin with Cryptomatte Layers disabled but Cryptomatte Raw Data enabled...

[Longbongosolo]

I'll also attach the EXR files as saved from Modo Octane and Blender Octane. I opened them in notepad and can see that the layer naming appears to be different. Modo Octane layers referenced with a 2 digit number eg. CryptoMaterialNode00.r and there are more of them whereas the Blender Octane file layers are named without a number and only referenced once each for R, G, B, A. I don't know if this means anything significant.

[linograndiotoy]

Thanks!

[Gutmann]

In my experience, If you're saving your image from the Blender Output Dialog, you'll get this problem. Layered EXR's (With Cryptomattes) will never be interpreted correctly in Photoshop using the EXR-io Plugin.

I've found, if you open the "Show Octane Viewport" under the "Octane Kernel" Tab and save your image out from there, you'll get what you're after. "Shows a Dialog to export the render passes" is the option you want to choose.

Also, make sure that under Camera Data Properties, that "Always Use Camera resolution" is checked on.
I also find it useful to check the "Pad Lock" on in the Octane Viewport, so that you don't inadvertently move the camera within the scene.