Hi VTK team,
using VTK 8.1.2 and Qt 5.14 (or earlier versions?), rendering semi-transparent meshes seems to be an issue…
When adding an RGBA cell array with transparency to our PolyData object or (alternatively) setting the actor’s opacity to something not equal to 1.0, in our Qt demo app, the PolyData object (Mesh) does not show up at all. With an opacity of 1.0, the mesh is displayed correctly (but without transparency)
I have tried approaching this problem according to
without success. In the latter case (no Qt), I could solve the visualization issue with the recommended call to ren.SetUseDepthPeeling(True), results show up as expected, but in our Qt app, meshes still get invisible after that call.
I have once tried VTK 8.2.0, but this has introduced other problems in the Qt application due to some strange event errors, making our demonstrator unusable (similar to https://gitlab.kitware.com/vtk/vtk/issues/17572).
Any advise on how to display semi-transparent PolyData in a Qt application? What Qt and VTK version should we use?