I am trying to parallelize rendering using blender's python API, built as a python module. I'd like to use multiple instances of blender contained within their own classes. Currently, I can generate multiple instances by running a script multiple times, but cannot have two functioning instances of the class in the same script, due to how bpy uses import to initialize the blender instance. Is there a way to get around this? A cut down version of the class is below.

class BpyRenderer(object):
    import bpy
    def __init__(self):
    def render(self, filename):
        self.bpy.data.scenes['Scene'].render.filepath = filename
        self.bpy.ops.render.render( write_still=True )
  • $\begingroup$ Have you already tried with threads? $\endgroup$
    – yhoyo
    Aug 8, 2018 at 1:47
  • $\begingroup$ One thread works, two conflict and the second one works but the first fails. I tested it with each thread object importing the BpyRenderer and loading a model. $\endgroup$
    – bokorn
    Aug 8, 2018 at 15:49

1 Answer 1


Blender only allows one render to run in each instance. As a single render instance will normally use all available cpu's there isn't usually any benefit to running multiple renders at the same time.

If you do want to run multiple renders at the same time, you will either need to run multiple instances of your script or of blender.

  • $\begingroup$ I want multiple instances of blender because the choke point is in loading the models for my problem, and I want some instances loading while others are rendering. I can have each one run independently and communicate over sockets, but was wondering if there was a cleaner. $\endgroup$
    – bokorn
    Aug 8, 2018 at 15:56
  • $\begingroup$ Running multiple renders at once would all work from the same scene and model data, so you don't want them all running from the same scene, you actually want to start a new process for each model. $\endgroup$
    – sambler
    Aug 8, 2018 at 19:32
  • $\begingroup$ Yes, is there a way of doing that without running multiple instances of a python interpreter i.e. making bpy generate another instance of blender? $\endgroup$
    – bokorn
    Aug 8, 2018 at 22:36

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