Material ID and Material Select render elements in V-Ray 5

[JeremyLondonMDL]

Can somebody please explain to me how to use the Material ID and Material Select render elements in V-Ray 5.

In V-Ray 3.7 each Material ID render element has a manually entered number field to determine which material it represents. In V-Ray 5 neither the Material ID or Material Select render elements appear to have this function (see attached images), and the render results for these elements are plain black.

I'm running V-Ray 5.2 with Cinema 4D R21.

Thanks

[aleksandar.kasabov]

Hello JeremyLondonMDL,

The material ID render element will create a mask, based on the material ID color, set in the Options section in the material editor. Adding the material ID RE and rendering the image (given that you have enabled the material ID of the material) will render a mask. For more information about this render element, you can refer to our documentation page.

You can also check this thread where Ivan explains the differences between the ObjectID and MaterialID Render Elements in V-Ray 3 and V-Ray 5.

As per the Material Select render element, please note that at the moment the input options for this render element are missing. This has already been discussed here and it is reported to our developers for fixing (bug ID: VC4D-739). I keep you updated on the progress. Thank you.

[JeremyLondonMDL]

Hi aleksandar.kasabov, thanks for this information.

The explanation and the video in the thread you linked was very helpful in understanding how the 'Material ID' in V-Ray 3.7 actually worked.

In regard to the true Material ID render element in V-Ray 5, I've found that it doesn't work for me (i.e. renders plain black, despite the materials having Material Id enabled and a Material ID color assigned to them) if the Color Mapping option is ticked in the Material ID render element options. I finally got the Material ID render element to work today by un-ticking this option. Can you confirm if this is the intended behavior, or a bug?

I'm running V-Ray 5 for Cinema 4D v5.20.05 with C4D R21.

[aleksandar.kasabov]

Hello JeremyLondonMDL,

When testing on my end I didn't experience any issues with the Material ID render element (both with Color Mapping enabled and disabled). Can you please specify if you are rendering with V-Ray or V-Ray GPU, your OS, sampler type, and other information about your scene? Are you rendering in the VFB or the Picture Viewer? Thank you.

[aleksandar.kasabov]

Hello JeremyLondonMDL,

As I already mentioned here, with the release of V-Ray 6 for Cinema4D we fixed the input options for the Material Select RE. You can download and install the latest version from here. You can also check what is new in V-Ray 6 here.