Function face_triangles_uv 

pub fn face_triangles_uv(
    model: &Model,
    face: &Face,
    n: usize,
) -> GeopResult<(Vec<Triangle2>, Vec<Vec<Vector2>>)>

face‘s trimmed region triangulated in (u, v) space, by a grid sized by the face’s curvature and clipped to its trim (see [grid::triangulate_face]), each triangle by its corners — and the trim it covers: its loops as the polygons of its edges’ samples, the outer first.