Skip to content

BUG: Force image slice actors to be treated as opaque

Sam Horvath requested to merge github/fork/msmolens/4253-image-slice-rendering-opengl2 into master

Created by: msmolens

This commit fixes rendering of image slices in the 3D view with the VTK OpenGL2 backend.

The OpenGL2 backend performs more thorough checks than the old backend when determining whether to treat an actor as opaque or translucent. Now, in certain cases, VTK determines that the slice texture contains transparent elements and therefore should treat the actor as translucent, i.e. rendered without writing to the depth buffer. [1][2]

This commit overrides that transparency-detection logic to force the image slice actors to be treated as opaque.

Fixes http://www.na-mic.org/Bug/view.php?id=4253

[1] https://github.com/Kitware/VTK/blob/bace0bcf81dd6e8d334b78add2d77da37d71398f/Rendering/Core/vtkActor.cxx#L131-L133

[2] https://github.com/Kitware/VTK/blob/bace0bcf81dd6e8d334b78add2d77da37d71398f/Rendering/OpenGL2/vtkOpenGLActor.cxx#L59

Merge request reports