There appears to be order of magnitude (from ~15 ms/frame to ~150 ms/frame) degradation in slice scrolling performance when volume rendering is enabled (slice is not shown in 3d view).
See demo in this screencast: https://www.screencast.com/t/fJ9O9N2El
This was done on a mac with the latest nightly.
Are you able to reproduce the problem when building against Qt5 ? (which will enable VTK8 and the latest OpenGL backend)
I can try this after Friday (or Friday afternoon).
The reason you get all those reports from me is that I am preparing for a tutorial, which I plan to dry-run tomorrow morning, and I report things as they show up … I hope this is helpful.
That is great. Then, we will be in good shape for the next release
The performance drop is the same in Qt5. If ‘Quality control’ is set to maximum, it’s even more noticeable.
I’ve entered a ticket to track the resolution of this issue:
https://issues.slicer.org/view.php?id=4423