Use Bullet for convex hull

Github: https://github.com/nicholasbishop/blender/commits/convex-hull-bullet

Commit messages
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Bullet convex hull: add access to the original indices for vertices

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Bullet: add convex hull computer to C API

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Partially replace convex hull implementation with Bullet implementation

* Bullet's convex hull implementation is significantly more robust than the one I implemented, as well as being faster.

* This fixes bug [#32864] Convex Hull fails in some cases.

  That bug, and others like it, relate to the poor handling of co-planar surfaces in the input. Pretty much any model that is simple-subdivided a few times gave very bad results before, Bullet's implementation handles this much better.

* In order to ensure a smooth transition, the Bullet output is translated into the existing HullTriangle hash structure. This makes it easy to ensure that the existing slot output stays the same; the interactions between the slots are somewhat complicated, detangling is a TODO.

[brechtvl, 2012-10-23 18:33:23]

Looks ok to me, also works well in some tests. If scons files are updated too
this LGTM.

https://codereview.appspot.com/6741063/diff/1/source/blender/editors/mesh/CMa...
File source/blender/editors/mesh/CMakeLists.txt (right):

https://codereview.appspot.com/6741063/diff/1/source/blender/editors/mesh/CMa...
source/blender/editors/mesh/CMakeLists.txt:77: add_definitions(-DUSE_BULLET)
The convention is to use -DWITH_BULLET, although it looks like this is already
inconsistent elsewhere.

More importantly though, this should be add to SConscript too in both
editors/mesh/ and bmesh/.

[nicholasbishop, 2012-10-23 23:56:14]

Thanks for reviewing, committed as r51557 and r51558 with the scons fixes.

On 2012/10/23 18:33:23, brechtvl wrote:
> Looks ok to me, also works well in some tests. If scons files are updated too
> this LGTM.
> 
>
https://codereview.appspot.com/6741063/diff/1/source/blender/editors/mesh/CMa...
> File source/blender/editors/mesh/CMakeLists.txt (right):
> 
>
https://codereview.appspot.com/6741063/diff/1/source/blender/editors/mesh/CMa...
> source/blender/editors/mesh/CMakeLists.txt:77: add_definitions(-DUSE_BULLET)
> The convention is to use -DWITH_BULLET, although it looks like this is already
> inconsistent elsewhere.
> 
> More importantly though, this should be add to SConscript too in both
> editors/mesh/ and bmesh/.