Blank Canvas (Unflushed Rendering) of PlantGL from L-Py animate()

[deltayoung]

I would like to report a rendering issue that appears since the migration of L-py / PlantGL libraries from Python 2 to Python 3.

From third-party program, OpenAlea.lpy.lsystem.animate() will open PlantGL Viewer to show animation of an L-system in Python 2 without problem.

However, if I run animate() in Python 3, it results in a blank canvas on PlantGL Viewer. I can only display the last frame of the animation if I put some input line such as "input()" or "raw_input()" following the animate() that seems to flush the rendering to show the last frame onto the blank canvas.

I tried to locate the implementation of lsystem.animate() in openalea Github repo to fix it on my end but could not find it. Kindly help. Thanks!

[fredboudon]

If you use it in a Qt application, it should not be a pb. If you use it in a shell script, you should use ipython --gui=qt5.