Blender Git Loki

Sculpt: Weight normal and area sampling towards the brush center

Previously, all vertices inside the brush radius were taken into account
equally when calculating the sculpt normal and area. This was causing
artifacts and unpredictable results with large brushes or meshes with
curvatures, as the strongest deformation point of all brushes is usually
in the center. By weighting the vertex normal and position towards the
center when sampling, all brushes should now behave in a more
predictable way in non-uniform surfaces.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D6989