1. add specific shader for thumbnail
2. do not render the negative-z part
3. fix the sinking related issue under cli
Change-Id: Ia59083437544c1c0bd924c811274ccbb137e9eb7
1. remove wireframe in 3d view, only keep in paint;
2. pass barycentric_coordinates from outside
3. add shortcut hints
Change-Id: I911e5cdf3475926d9527dc0839fdce072ed54746
(cherry picked from commit 6e16d0ccfb71741e55daabd757be9f9e7613e695)
1. set the unprintable volume to black even if it is mmu painted
2. add the bounding check logic when the object is partly inside of current plate
Change-Id: I69ce25eb85a71398ed8fb1d275136c5d943796d6
