multiblock performance regression
This issue was created automatically from an original Mantis Issue. Further discussion may take place here.
After updating to VTK 5.10.1, we eventually found our rendering performance had decreased about 3 times for some models.
I narrowed it down to vtkCompositePolyDataMapper2::GetIsOpaque(). We have few mappers with hundreds or thousands of datasets. What used to take about .6 seconds to render a scene, now takes about 2 seconds. I can derive from the class and reimplement GetIsOpaque to return true, and my speed goes back to .6 seconds per render.
I was using vtkCompositePolyDataMapper2 because a previous upgrade made many vtkActor objects slow. So I rearranged my code to use few actors. But now another upgrade has slowed that down as well. I also manually defer garbage collection when I can to get even more speed ups. Bottom line, VTK seems to get heaver and slower with each release.