Adding AOV shader with custom Image format to Arnold ROP

[Michael_Parker]

Hi..

So we'd like to add our own AOV shader that has a custom Image format to the Arnold ROP. The shader provides cryptomatte like object ID's as an AOV. We have this working in MtoA, so assume it's possible in HtoA as well.

2 part question I guess.

It looks like we can add custom AOV shaders in the Output Tab, however this only appears to let us point to a top level arnold shading network container. As our custom shader appears available within the shader network itself and not the top level. Do we just need to place this inside an empty container, or do we need to hook it up via the OUT_material or other nodes for it to be recognised?

The second part, is that the shader uses a custom image format - and we were wondering if there was a way to add a custom image format to the drop down list, which by default consists of OpenEXR, DeepOpenEXR, TIFF, PNG, JPEG etc.

Hope that makes sense, happy to clarify further if need be.

Thanks!

[ashley.handscomb.retallack]

Custom drivers are not supported currently, this is a known issue.

To use a custom AOV shader you need to create an Arnold Shading Network adn inside that create an AOV_out node, then conenct your AOV shader to one of the inputs.

The basic AOV shader workflow is decribed in the cryptomatte tutorial here: https://docs.arnoldrenderer.com/x/lxNSAw