This commit changes the Clay Strips brush in the following ways:
* Removes hardcoded displacement and scaling of brush matrix
* Applies a falloff to the factor based on the distance to the point in
the brush-local z-axis
This change has the effect of reducing the brush influence on nearby or
other back-facing planes, reducing overall unwanted deformations.
Pull Request: https://projects.blender.org/blender/blender/pulls/128775