One of the strange thing about supporting Arnold at Autodesk is that you have to be a guru-level licensing expert on Autodesk licensing (not RLM, but Autodesk licensing).
In this case, Maya 2019 would silently fail at startup. Sometimes you’d see the splash screen, but then that would just disappear.
- There was nothing in the Adlm.log
- No MayaAdlm log was created
TIP All these log files are in the Temp folder.
- On Windows, look in %LOCALAPPDATA%\Autodesk\Logs
- On OSX, look in $TMPDIR
- On Linux, look in /var/tmp
Process Monitor confirmed that the ProductInformation.pit file was missing:
ProductInformation.pit is an all-important file used by the licensing infrastructure. Every Autodesk product must be registered in that pit file.
If ProductInformation.pit is missing, or corrupted, then everything stops working.
Or: how to fix the node “xgen_procedural” is not installed problem.
For example, suppose you want to render XGen hair in CINEMA 4D on macOS.
If you see this warning when you render
Warning: [mtoa] [translator polymesh] ShadingGroup exampleSG has no surfaceShader input
it’s because a shadingEngine node either has nothing connected to the surfaceShader port, or (more likely) it has an unknown node plugged into surfaceShader.
For example, if you load a scene that was set up with a different renderer, and that renderer is not loaded, then you’ll get some “ShadingGroup has no surfaceShader input” warnings.
You can use use color_correct with alpha_is_luminance enabled, like this:
This error means that you are trying to render multiple AOVs into a single file, and the file format (PNG in this example) does not support that.
JPEG, PNG, and TIFF cannot have multiple AOVs in a single file. The AOVs have to be rendered in separate files.
If you get this error, check the Common tab. If you don’t see the <RenderPass> token, then you’re going to get the “more than one output statement was associated with single layer driver” error.
For JPEG, PNG, and TIFF, you need the <RenderPass> token:
Normally, MtoA will automatically add the <RenderPass> token for you. But sometimes Merge AOVs gets enabled for EXRs, and then the Image format is changed to another format, like PNG.
So just switch back to EXR and disable Merge AOVs. Then switch back to the other image format.
If you want to control object visibility with operator, or the Arnold Python API, or by editing an ASS file, you need to understand Arnold’s visibility parameter.
In the UI, the object visibility options look like a bunch of separate parameters:
but in Arnold, all those options are stored in one visibility parameter.
For example, if an object is visible to the camera (primary visibility), and to transmission (both diffuse and specular), then that’s visibility 13.
Why 13? Because 13 = 1 + 4 + 8
- camera rays = 1
- diffuse transmission rays = 4
- specular transmission rays = 8
The Arnold visibility parameter tells Arnold the rays to which the object is visible.
- visibility 0 means the object isn’t visible to any rays
- visibility 255 means the object is visible to all rays
- visibility 253 means the object isn’t visible to shadow rays (so the object does not cast shadows).
Here’s the decimal values for all the different ray types.
To figure out the visibility, just add up the values for the rays you want.
|Ray type||Decimal Value|
|Camera (Primary Visibility)||1|
|Shadow (Casts Shadows)||2|
There’s two denoisers. Here’s when to use them:
- Use the OptiX Denoiser for fast (GPU-powered), slightly-lower quality denoising of IPR
- Use the Arnold Denoiser (aka noice) for high-quality denoising of final frames and animation sequences
For more info, check the docs