When using part_render there is one problem left, and that is that the object (the circle in the example) gets drawn with default values at the center,and is not actually a particle (You can check this by setting the part_size value in the 07.render.pd examples of the particle patches to a small value like 0.1)
To get rid of that problem, some chances in GemBase.cpp have to be introduced. There are several possibilities:
1) make gem_renderMess a virtual function and reimplement it in part_render.cpp without the problematic gem_state message
drawback: virtual functions are slow
2) provide some mechanism to suppress the message (setting a flag in the GemBase class)
drawback: a bit hacky
3) call continueRender at the end of every render() call
drawback: lots of work
I have implemented the first version already, could commit it, but I want to hear what you think first.
Guenter