Function bevel

scripts/repousse.py:207–276

(wires, logger, remove_holes, dist)

    return mesh;

def bevel(wires, logger, remove_holes, dist):
    bbox_min, bbox_max = wires.bbox;

    #wires = uniform_sampling(wires);
    mesh = constrained_triangulate(wires, logger, remove_holes);

    cell_ids = mesh.get_attribute("cell").ravel().astype(int);
    num_cells = np.amax(cell_ids) + 1;

    comps = [];
    for i in range(num_cells):
        to_keep = np.arange(mesh.num_faces, dtype=int)[cell_ids == i];
        if not np.any(to_keep):
            continue;

        cut_mesh = pymesh.submesh(mesh, to_keep, 0);
        bd_edges = cut_mesh.boundary_edges;
        vertices, edges, __ = pymesh.remove_isolated_vertices_raw(
                cut_mesh.vertices, bd_edges);
        bd_wires = pymesh.wires.WireNetwork.create_from_data(vertices, edges);

        offset_dir = np.zeros((bd_wires.num_vertices, 2));
        for ei in edges:
            v0 = ei[0];
            v1 = ei[1];
            adj_vts = bd_wires.get_vertex_neighbors(v0);
            if len(adj_vts) == 2:
                if adj_vts[0] == v1:
                    vp = adj_vts[1];
                else:
                    vp = adj_vts[0];
                e0 = vertices[v1] - vertices[v0];
                e1 = vertices[vp] - vertices[v0];
                e0 /= norm(e0);
                e1 /= norm(e1);
                theta = math.atan2(e0[0]*e1[1] - e0[1]*e1[0], e0.dot(e1));

                if abs(theta) > 0.99 * math.pi:
                    offset = np.array([-e0[1], e0[0]]);
                    scale = 1.0;
                else:
                    if theta > 0:
                        offset = e0 + e1;
                        scale = math.sin(theta/2);
                    else:
                        offset = -e0 - e1
                        scale = math.cos(math.pi/2 + theta/2);
                    offset /= norm(offset);
                offset_dir[v0] = offset * dist / scale;

        offset_vertices = vertices + offset_dir;
        vertices = np.vstack((vertices, offset_vertices));
        edges = np.vstack((edges, edges + bd_wires.num_vertices));

        vertices, edges, __ = pymesh.remove_duplicated_vertices_raw(
                vertices, edges, dist/2);

        comp_wires = pymesh.wires.WireNetwork.create_from_data(vertices, edges);