Hi Ben & Sankhesh.
Thanks for the swift reply. I have one other data point that probably rule out Qt as the problem. The following dependency settings also exhibit the problem:
Qt 5.15.2
VTK 9.0.3
PCL 1.12.0
Now, that does not remove Qt completely as a cause. Cf. e.g. “VTK 8.2, performance degradation on upgrade Qt 5.12 -> 5.15 - #3 by lassoan”. Someone suggest anti-aliasing changes. Do you think that could have an impact and explain the higher GPU usage?
As for errors, then we get the warnings shown here: https://gitlab.kitware.com/vtk/vtk/-/issues/18663, but I suspect that is not so relevant.
As Ben suggest, we can try going back further. It’s not always easy because of interdependencies between PCL and VTK.
We’ll try to figure out what is taking time in render.
kind regards
Thorsten