use cadquery to facet

[shimwell]

instead of installing gmsh we could potential use cadquery to facet the geometry.

here is some code that doesn't quite produce watertight geometry but looks like it is close

this didn't produce non overlapping water tight parts when the geometry was in contact with other surfaces
def tessellate(parts, tolerance: float = 0.1, angularTolerance: float = 0.1):
    """Creates a mesh / faceting / tessellation of the surface"""

    parts.mesh(tolerance, angularTolerance)

    offset = 0

    vertices: List[Vector] = []
    triangles = {}

    for f in parts.Faces():

        loc = TopLoc_Location()
        poly = BRep_Tool.Triangulation_s(f.wrapped, loc)
        Trsf = loc.Transformation()

        reverse = (
            True
            if f.wrapped.Orientation() == TopAbs_Orientation.TopAbs_REVERSED
            else False
        )

        # add vertices
        face_verticles = [
            (v.X(), v.Y(), v.Z()) for v in (v.Transformed(Trsf) for v in poly.Nodes())
        ]
        vertices += face_verticles

        face_triangles = [
            (
                t.Value(1) + offset - 1,
                t.Value(3) + offset - 1,
                t.Value(2) + offset - 1,
            )
            if reverse
            else (
                t.Value(1) + offset - 1,
                t.Value(2) + offset - 1,
                t.Value(3) + offset - 1,
            )
            for t in poly.Triangles()
        ]
        triangles[f.hashCode()] = face_triangles

        offset += poly.NbNodes()

    list_of_triangles_per_solid = []
    for s in parts.Solids():
        triangles_on_solid = []
        for f in s.Faces():
            triangles_on_solid += triangles[f.hashCode()]
        list_of_triangles_per_solid.append(triangles_on_solid)
    for vert in vertices:
    for tri in list_of_triangles_per_solid:
    return vertices, list_of_triangles_per_solid

[shimwell]

this would need to work for an imprinted assembly instead of parts

import cadquery as cq
assembly = cq.Assembly(name="TwoTouchingCuboids")
cuboid1 = cq.Workplane().box(10,10,10)
assembly.add(cuboid1)
cuboid2 = cq.Workplane().moveTo(5,5).box(3,3,3)
assembly.add(cuboid2)
imprinted_assembly, _ = cq.occ_impl.assembly.imprint(assembly)