Users can set distance between support bottom contacts and object
once enable normal/tree support.
Jira: STUDIO-1383
TODO:Func seems good though, some details (e.g., bottom_interface
detection) need to be optimized furthur. Will keep follow-up.
Change-Id: I85815e7aa6cf1a5d0249633cd8ab995873461e8a
(cherry picked from commit eab39e89c94d749ebe6266ab745cbb70a068277d)