Some bugfixes and minor additions from 2.6:

• Unbreak ground shadows
• Fix some bounding box numerical issues for degenerate scenes
• Adjust transform gizmo background color
• Wireframe visualization for sparse grid structures

Python

• Add (very beta) support for Gaussian splats, via the gsplat library. See https://github.com/nmwsharp/polyscope-py/blob/master/test/scripts/gaussians_demo.py