Function polytope_section_faces_append 

pub fn polytope_section_faces_append(
    edges: &[[u32; 2]],
    cells: &[&[u32]],
    vertices: &[Vec4],
    slice: WPlane,
    color: [f32; 4],
    scratch: &mut SectionScratch,
    out: &mut TriangleMesh<3>,
)