Blender Git Loki

Radical simplification of the wind effect on hair, since the previous
approach does not work very well.

Using a cross section estimate still causes large oscillations due to
varying hair force based on angles. It also requires a sensible hair
thickness value (particle radius) which is difficult to control and
visualize at this point.

The new model is based purely on per-vertex forces, which seems to be
much more stable. It's also somewhat justified by the fact that each
hair vertex represents a certain mass.

Facemap bones now draw properly. It's not possible yet to select the
bones so use with caution.

Fix more crashes when removing facemaps. Indices of leftover facemaps
above the deleted one could become invalid

More silly mistakes in widget move code.

Stubs for new facemap widget, fixes for facemaps.

Move/remove facemap not working well (probably was never working but by
displaying them has actually made the issue apparent)

Fix crash with decimate modifier on zero.

Fixes to facemaps:

* Test display code that displays the active facemap. Will not work on
subsurf modifier yet (crash)
* Fix loading of files with facemaps
* Facemap data now reside on polys instead of tessfaces.

Merge branch 'master' into wiggly-widgets

Code that will draw a transparent overlay of a facemap over the mesh
(crashes atm).

Improved force field effects on hair strands.

The previous calculation was modulated with the angle between the wind
direction and the segments, which leads to very oscillating behavior.

Now the formula includes an estimate for the geometric cross section
of a hair segment based on the incident angle and the hair thickness
(currently just the particle size). This gives a more stable behavior
and more realistic response to wind.

Add code that copies sorted per facemap vertex indices to a VBO buffer

Initial VBO code for GPU subsurf.

This commit adds a few generalizations to the VBO
code so that modifiers can create and populate their own GPU objects.

The VBO code originally supported CDDerivedMesh only. The design moves
slightly towards the viewport refactor where the rendering system
requests data from modifiers.

What we do have is support for solid shading with multiple
materials, flat/smooth shading and a big performance boost.
Performance could

In this commit only basic support for vertices and normals is provided
and some features from blender's VBO system, such as mapping to
original faces, unique element indices for vertices and loose vertex/
and can be added later. The one feature that is missing now is the quick
navigation feature of the multires modifier (which uses the same code).

- Why this commit is made on the widget branch -

Facemap widgets need to avoid drawing the whole mesh when we do
collision detection on them. For subsurf drawing we need to iterate
through the whole mesh every time. What we need instead is sort
indexed elemet drawing according to the facemap each face belongs to.
This screams VBOs but since I was going to add that, I thought that
I could push it a bit further and add proper solid shading support.

Revert "Initial VBO code for GPU subsurf."

This reverts commit 7163ddf53e6f5f67c59a8dfc14f60515f8f577c7.

Initial VBO code for GPU subsurf.

This commit adds a few generalizations to the VBO
code so that modifiers can create and populate their own GPU objects.

The VBO code originally supported CDDerivedMesh only. The design moves
slightly towards the viewport refactor where the rendering system
requests data from modifiers.

In this commit only basic support for vertices and normals is provided
and some features from blender's VBO system, such as mapping to
original faces, unique element indices for vertices and loose vertex/
and can be added later. The one feature that is missing now is the quick
navigation feature of the multires modifier (which uses the same code).

What we do have is full support for solid shading with multiple
materials, flat/smooth shading and a big performance boost.
Performance could

- Why this commit is made on the widget branch -

Facemap widgets need to avoid drawing the whole mesh when we do
collision detection on them. For subsurf drawing we need to iterate
through the whole mesh every time. What we need instead is sort
indexed elemet drawing according to the facemap each face belongs to.
This screams VBOs but since I was going to add that, I thought that
I could push it a bit further and add proper solid shading support.

New python submodule `mathutils.interpolate` for various mesh interpolation and weighting methods.

This module will contain mirrored functions for calculating and applying
weights for points on a mesh. This includes barycentric and UV weighting
and possibly more advanced global weighting such as harmonic weights.

The naming should follow this scheme:
<type>_{2d,3d}_{calc,apply}

e.g.
poly_2d_calc
poly_2d_apply
uv_3d_calc
...

Reviewers: campbellbarton

Differential Revision: https://developer.blender.org/D939

Merge branch 'master' into wiggly-widgets

Placeholder GPU functions to get GPU facemap index buffer. API should
allow a widget to draw a specific facemap bound to a mesh quickly.

Fix selection id not getting incremented in face-map bones

Merge branch 'wiggly-widgets' into gooseberry

Deactivate irritating shapekey widget while it's still under
development.