Sculpt: add Topology Rake, to align edges along brush while painting.

This helps to generate cleaner topology and define sharp features for dynamic
topology. Best used on relatively low-poly meshes, it is not needed as much
for high detail areas and has a performance impact.

Differential Revision: https://developer.blender.org/D4189

release/scripts/startup/bl_ui/space_view3d_toolbar.py

@@ -270,6 +270,13 @@ class VIEW3D_PT_tools_brush(Panel, View3DPaintPanel):
             if not self.is_popover:
                 brush_basic_sculpt_settings(col, context, brush)
 
+            # topology_rake_factor
+            if capabilities.has_topology_rake and \
+               context.sculpt_object.use_dynamic_topology_sculpting:
+                col.separator()
+                row = col.row()
+                row.prop(brush, "topology_rake_factor", slider=True)
+
             # auto_smooth_factor and use_inverse_smooth_pressure
             if capabilities.has_auto_smooth:
                 col.separator()