VNF meshes

class bosl2.vnf.VNF(vertices=(), faces=())[source]

Bases: object

A VNF surface: vertices (3-D points) plus faces (index polygons into vertices).

Renders to PythonSCAD’s native polyhedron via polyhedron(). Build one from a rectangular grid of sample points with vertex_array(), and merge several with join().

Parameters:

  • vertices – list of [x, y, z] points

  • faces – list of index lists (each polygon into vertices)

Examples

Meshing a bumpy grid of sample points into a surface and rendering it as a polyhedron:

grid = [[[x, y, 4 * math.sin(x / 6) * math.cos(y / 6)] for y in range(0, 60, 4)]
        for x in range(0, 60, 4)]
VNF.vertex_array(grid).polyhedron().show()

⬇ Download STL mesh

bounds()[source]

[[min_x, min_y, min_z], [max_x, max_y, max_z]].

Return type:

ndarray

reverse()[source]

A copy with every face wound the other way (flips the surface normals).

Return type:

VNF

volume()[source]

Signed enclosed volume (BOSL2 vnf_volume()); negative when the faces wind inward.

Used to detect and fix inverted meshes (a swept/skinned surface whose winding came out inside-out): vnf if vnf.volume() >= 0 else vnf.reverse().

Return type:

float

static join(vnfs)[source]

Merge a list of VNFs into one, offsetting each VNF’s face indices (BOSL2 vnf_join()).

Return type:

VNF

classmethod vertex_array(points, caps=None, cap1=None, cap2=None, col_wrap=False, row_wrap=False, reverse=False, style='default')[source]

Build a VNF from a rectangular grid of 3-D points (BOSL2 vnf_vertex_array()).

Each grid cell becomes triangles (or a quad) chosen by style: “default”, “alt”, “min_edge”, “min_area”, “convex”, “concave”, “quincunx”, “quad”, “flip1”, “flip2”. col_wrap/row_wrap close the grid into a tube/torus; caps/cap1/cap2 close the column-wrapped ends; reverse flips face winding. Degenerate (zero-area) faces are dropped.

Parameters:

  • col_wrap (bool)

  • row_wrap (bool)

  • reverse (bool)

  • style (str)

Return type:

VNF

classmethod tri_array(points, caps=None, cap1=None, cap2=None, col_wrap=False, row_wrap=False, reverse=False, limit_bunching=True)[source]

Build a VNF from an array of rows whose lengths may differ (BOSL2 vnf_tri_array()).

Triangulates between adjacent rows by repeatedly adding the shortest new edge, so it meshes triangular / irregular point arrays (what the degenerate bezier patches produce).

Parameters:

  • col_wrap (bool)

  • row_wrap (bool)

  • reverse (bool)

  • limit_bunching (bool)

Return type:

VNF

polyhedron()[source]

Native geometry for this VNF via PythonSCAD’s polyhedron(points=, faces=).

geometry()[source]

Alias of polyhedron(), matching Path/Region’s geometry() surface.