Opacity issues

[Jellby]

It is common to see artifacts in translucent object in any 3D rendering software, but I wonder if there is something that could be done to alleviate them in Mayavi. I took the "atomic orbital" example, added opacity=0.8, and this more or less shows the issue, as I slightly tilt the object from left to right:

The center figure shows obvious artifacts, but it is also clear (at least when seeing it "live") that there is something wrong in the right figure: for instance, the pink-blue part of the surface should stay at the top right, and not the top left.

I also see things similar to this, and it is suggested that "depth peeling" could help. Can I enable it with Mayavi? How?

[larsoner]

I tried for a while to get depth peeling to work by digging into tvtk and even vtk itself but was never able to. :(

[prabhuramachandran]

I tried this:

s = mlab.pipeline.surface(contour2, colormap='hsv', opacity=0.8)
s.scene.renderer.use_depth_peeling = True

And it seems to look pretty good to me with VTK 8.1.1. Also you could try increasing

s.scene.renderer.maximum_number_of_peels = 8

I am unable to reproduce this so am closing this for now. Please reopen if you are running into issues.

[larsoner]

I can confirm that changing s.scene.renderer.use_depth_peeling does change behavior on my system (macOS, VTK 8.1.0)