Mesh with a single Point primitive.
The PointMesh is made from a single point. Instead of relying on triangles, points are rendered as a single rectangle on the screen with a constant size. They are intended to be used with Particle systems, but can be used as a cheap way to render constant size billboarded sprites (for example in a point cloud).
PointMeshes, must be used with a material that has a point size. Point size can be accessed in a shader with
POINT_SIZE, or in a SpatialMaterial by setting SpatialMaterial.flags_use_point_size and the variable SpatialMaterial.params_point_size.
When using PointMeshes, properties that normally alter vertices will be ignored, including billboard mode, grow, and cull face.