Blender Git Loki

PointCloud: Change visualization to use octahedron

This reduces the number of polygon needed. Also optimize
the case when pointcloud has uniform radius.

PointCloud: Initial rendering support for Workbench

Also includes outline overlays. Removes the temp overlay drawing

We make the geometry follow camera like billboards this uses less
geometry. Currently we use half octahedron for now. Goal would be
to use icospheres.

This patch also optimize the case when pointcloud has uniform radius.
However we should premultiply the radius prop by the default radius
beforehand to avoid a multiplication on CPU.

Differential Revision: https://developer.blender.org/D8301

PointCloud: Make geometry follow camera

A bit like billboards. This will allow to use less geometry
in the future.

PointCloud: Initial rendering support for Workbench

Also includes outline overlays. Removes the temp overlay drawing

DRW: Add common point cloud rendering functions