Cool! 👍🏻
Will look into this on Community Day.

Pushed new branch T26653-ReenableDepthPeeling.

@maleike

I re-enabled depth peeling support based on your pull request and also enabled depth peeling for volumes and FXAA. It works well for surfaces and volumes but totally breaks rendering of images/cross hair with opacity < 1. So this is not yet complete and I/we have to fix this before I am able to merge it.

Also PointSets have a similar problem with opacity now.

All remaining issues solved by @maleike. I reintroduced the rendering mode preference but instead of switching between "Standard" (default, basically equivalent to "nothing") and "Depth Peeling" it now allows to switch between "No anti-aliasing" and "Fast Approximate Anti-Aliasing (FXAA)" (default). Depth peeling is always enabled as it only kicks in if there are translucent objects in the scene and in the worst case it is preferable to have not the fasted rendering instead of having a broken rendering. The future will show if we there is really a need to additionally add quality options regarding depth peeling.

Pushed new branch T26653-MasterIntegrationFixes.

In T26653#188477, @kislinsk wrote:

@maleike

I re-enabled depth peeling support based on your pull request and also enabled depth peeling for volumes and FXAA. It works well for surfaces and volumes but totally breaks rendering of images/cross hair with opacity < 1. So this is not yet complete and I/we have to fix this before I am able to merge it.

Wow, I never noticed your comment here before I saw your reaction to the update on my GitHub pull request.. No idea why.. (checked all my mails and Phabricator settings)

Well anyways, thanks for integrating all of that and for your completion work! Perhaps I would have come up with the VTK patch earlier if I had seen your comment. I actually fixed vtkPropAssemblies because of a visualization issue completely unrelated to the crosshair.