If a clean install of MtoA doesn’t work (and the computer does support SSE4.1), then “The specified module could not be found.” usually means there’s a missing dependency. Dependency Walker is a decent, if aging, tool for checking out dependencies, but for leaving no stone unturned, I prefer Process Monitor.
The MtoA plugin (mtoa.mll) depends on a handful of files only. Here’s the log of loaded DLLs for a working MtoA:
Here’s a quick walkthrough (no audio) of how to get a Process Monitor log:
The Arnold volume node uses the texture search path, so you don’t have to use an absolute path in the volume filename.
So if you need to set up a Maya scene so that the OpenVDB volumes work on any platform, you could put an environment variable in the Texture Search Path
Just note that support for volume filenames is still a little … rough. You can’t enter an absolute path in the aiVolume Filename box, then enter a texture search path, and expect MtoA to automatically export a relative path. That still needs to be implemented.
For now, here’s what to do:
When you first create the volume, load the vdb file and leave the full absolute path in the aiVolume Filename box.
Select the grids and set the other volume parameters.
Then set the texture search path and strip off the path from the volume file name (leaving just the file name).
Now the environment variable will control where Arnold looks for the vdb file.
The Arnold volume node also support environment variables, so you could do this:
But again, once you put the environment variable into the Filename, the path won’t be resolved inside Maya (but it will work when you render).
To jitter color with user data, you need to connect an aiUserDataInt to the data input parameter, like this:
The user data is an mtoa_constant attribute on the shape. For example, if add an extra attribute named mtoa_constant_jitterID to some shapes, then you can use aiUserDataInt to read the jitterID.
jitterID is set on the shape
Jitter by user data (with a little jitter per face too)
aiUserDataInt reads the jitterID
If you want to use the shapes as standins, and be able to set the jitterID in the scene, then export the shapes without the mtoa_constant_jitterID attribute. In the scene, you’ll be able to add mtoa_constant_jitterID to the aiStandin node. The aiUserDataInt node in the ASS file will use that jitterID.