Knife tool. Make the drawing anti aliased and consistent by using 3D_POLYLINE/3D_POINT shaders, and making sure alpha blending is on. Monkey work based on [[ https://developer.blender.org/D11333 | D11333 ]] done by [[ https://developer.blender.org/p/krash/ | Anthony Edlin (krash)]] Reviewed By: jbakker Differential Revision: https://developer.blender.org/D12287