Export triangle meshes in STL format

[kennyweiss]

Several queries in axom are based on STL triangle meshes (e.g. the In/Out and Signed distance query).

We also have a mesh_tester application that validates geometric and topological properties of an input STL mesh and performs some simple mesh repair.

However, we currently only have the ability to export triangle meshes in VTK format.

We should add the ability to write out STL meshes in ascii or binary format.

[gzagaris]

The VTK mesh can be read into VisIt which then can dump the mesh in STL (binary and ASCII).

[kennyweiss]

Thanks @gzagaris -- I'm aware of that, but in terms of workflow, I think it would be more convenient if the mesh_tester app could automatically output the welded/repaired mesh as an STL mesh.

It should be fairly easy to do this.

[gzagaris]

Agreed.

[kennyweiss]

We might also want to output/input triangle meshes in the blueprint format for In/Out, distance and shaping queries