Blender Git Loki

Cleanup: clang-format.

Fluid: Improvements in Phi grid display

* Changed field texture format from 'GPU_R8' to 'GPU_R16F' for level-set fields to avoid data normalisation.
* Fragment coloring for level-set fields is now dynamic and does not depend on transfer texture.

Merge branch 'master' into soc-2020-fluid-tools

Fix repeated UV vertices and their indices

`append`'s usage causes `export_mesh_eval->totloop` many UV vertices
being written to the OBJ file. There are duplicates in that list.

So _tot_uv_vertices is being used to track the unique ones.

Add support for exporting nurbs curves & surfaces

Added functionality in OBJNurbs & OBJWriter to export nurbs curve, not
as vertices and edges, but rather control points.

Nurbs surfaces are always converted to mesh and then exported as a
regular mesh with vertices, normals, UV (if it has any), and edges
(if it has no polygons) etc.

Minor clean up

init guess on x

several bugfixes but I think I'm going to need to change the way I handle constrained solve

Add support for curves to be exported as nurbs

GPencil: Update point index when stroke is updated

Review update: move more things to private access

Review as per D8089:

Add constructors and destructors for both OBJWriter and OBJMesh classes

Move more variables to private and access the required via getters.

Remove unnecessary variables.

Rename ob_mesh to export_mesh_data.

obstacle collisions. REALLY need to improve mass computation

Merge branch 'master' into greasepencil-edit-curve

Merge branch 'master' into greasepencil-object

Merge branch 'master' into greasepencil-edit-curve

Merge branch 'master' into greasepencil-object

Merge branch 'greasepencil-edit-curve' into soc-2020-greasepencil-curve

GPencil: Selection syncing from/to curve edit mode

Custom Menu: fix merge

Custom Menu: restruct rna and change enum button to button collection