Blender Git Loki

Separate buffer texture for hair index for each vertex.

This is needed for allowing variable length hair strands, where the hair index can not
simply be calculated from the vertex index based on a fixed-length strand.

Fix the hairStrandsRes uniform for particle hair.

Correct point and element counts for particle hair.

Post merge fixes.

Merge branch 'hair_guides' into tmp_hair_curves

Merge branch 'blender2.8' into hair_guides

Change the uniform strand_res value to strands_len, point_len and elem_len counts.

Rename proc_buf to proc_point_buf to make it consistent with the main control point buffer.

Merge branch 'hair_guides' into tmp_hair_curves

Merge branch 'blender2.8' into hair_guides

Merge branch 'hair_guides' into tmp_hair_curves

Merge branch 'blender2.8' into hair_guides

Construct hair strands data from hair systems (no real UV/MCol yet).

Extend default material function for Eevee to work with hair systems.

Fix a few minor crashes from unfinished hair shader code.

Remove the parent interpolation hair shader and use the transform-feedback shader instead.

Remove the mesh sample from fiber curve data.

Fiber curves are simple shapes for fibers now, not tied to a particular
place on the scalp mesh (cf. shape keys).

Fix fur curve generation function.

Simple hair curve generation for testing per-follicle curves.

Add common ui draw function for hair display settings.