Hmm, I’m not entirely sure what Python’s multiprocessing module is doing under the hood, but if it’s trying to spawn another instance of Python I do find it easy to believe that this might have problems in the p3d environment. This is because we’re running embedded Python, from a custom runtime environment; it’s not at all a straightforward Python process, and a child process might have to do special things to launch correctly.
I haven’t looked into this at all before. It’s possible that there’s just a simple thing that’s getting in the way and which is easily fixed; but it also might be that we will have to create a custom multiprocessing module in order to simulate Python’s standard behavior.
David