Blender Git Loki

Merge branch 'blender2.8' into hair_guides

Test API in the fur modifier for creating custom guide curves with python.

The fur modifier is just a testbed for the underlying hair system.
The API is intended to allow specifying guide curves with python scripts
without having to worry about inconsistent state. All curves are first
defined in a python-friendly way, then applied to the hair system in one step.

Alternative guide curve setter function that works better for RNA.

Move guide curve into a nested struct, so it can be replace in one operation.

Disable unfinished code.

Merge branch 'blender2.8' into hair_guides

Initial system for generating guide curves from groom.

Popup for setting hair distribution operator properties.

Fix outdated usage of BLI_task_parallel_range.

New operator for distributing hair follicles for a groom object.

Merge branch 'blender2.8' into hair_guides

Depsgraph cleanup for groom curve cache eval.

Operator for binding groom bundles to scalp regions.

Remove scalp binding from generic depsgraph groom updates, this should be an operator.

Merge branch 'blender2.8' into hair_guides

Disable rebinding during every update to prevent invalidating transform data.

Add back section edges drawing.

Calculate individual curves for each shape vertex.

This avoids overlap which happens on sharp turns when simply extending
the curve linearly from the center. It also simplifies the curve cache
data structure.

Sparser edge drawing for grooms to reduce visual clutter.

Shape binding for groom curves to the scalp mesh surface using face groups.

Face groups are used for now to define the origin of a groom bundle. This
is probably going to be replaced at some point with a dedicated surface
graph/mesh, but is much easier to implement and gives sufficient functionality.

When a face map is selected as the basis of a hair bundle it will update
the curve shape automatically. In the future this should perhaps be an
optional step (user operator) because it destructively changes existing
shapes.