Blender Git Loki

Fix T37177, sculpting can act on opposite side of mesh in orthographic camera.

Summary:
Issue here most probably is that the start point in ray-casting is too
far away from the mesh. As a result the triangle intersection code can
sometimes miss the ray intersection. To solve this, we project the ray
segment to the boundary of the root node.

Reviewers: brecht, sergey, campbellbarton

Reviewed By: brecht

Maniphest Tasks: T37177

Differential Revision: https://developer.blender.org/D115