v0.8.7

Features

• SparseVolumeGridData: sparse voxel grid type with per-cell and per-node scalar/color quantities
• Add Edge, Halfedge, and Corner attribute kinds: per-edge scalars averaged to vertices for smooth rendering.
  • Pick probing also extended to Edge, Halfedge, and Corner attributes
• Add PointCloudItem::radii and PointCloudItem::transparencies: per-point size and opacity overrides
• Add the ability to add glyphs at given vertexes.

Fixes

• Fix plasma and viridis colormap polynomial
• Fix tests/clip_volume.rs and tests/headless.rs which used the old ClipPlane and ClipVolume

Example updates

• Create showcase 31 for sparse volume grids
• Create showcase 32: edge/halfedge/corner scalar colouring, volume mesh vector arrows, and point cloud radius + transparency