Module mesh_formats

Expand description

Tessellated interchange: glTF 2.0, OBJ and PLY.

Three formats, one philosophy carried over from the DXF writer: the functions take bare tessellations rather than a model, so anything that produces a Triangulation (a solid, one face, a healed import) exports without this module knowing where it came from. glTF is written as GLB, the single-file binary form, with positions, normals, indices and an optional base colour per mesh; OBJ and PLY are the plain-text dialects every downstream tool reads.

§Reading is not writing backwards

What this module writes is one of many shapes each format allows, and a reader that assumed its own writer’s choices would read almost nothing. glTF is the sharp case: its geometry reaches the file through accessors over buffer views over buffers, any of which may stride, offset, use any of six component types, scale integers into fractions, or be overridden piecewise by a sparse block, and the whole is placed by a node hierarchy stated as a matrix or as translation, rotation and scale. All of that is read. What is not read is refused by name rather than approximated.

Structs§

ExportMesh: One mesh to export, with what the format can say about it.
ImportedMesh: One mesh read back out of a glTF document.
ObjImport: What read_obj_with_materials found.
PlyImport: What read_ply_bytes found.

Enums§

MeshColours: The colours a mesh read carries, in the most compact form that says exactly what the file said.

Functions§

read_glb: Read a GLB: glTF 2.0’s single-file binary form.
read_gltf: Read a .gltf: the JSON form, whose buffers are data URIs.
read_obj: Read an OBJ into a triangulation.
read_obj_file: Read an OBJ file from disk with its materials, as read_obj_with_materials reads them.
read_obj_with_materials: Read an OBJ with the colours its materials give it.
read_ply: Read a PLY into a triangulation.
read_ply_bytes: Read a PLY, ASCII or binary of either byte order, mesh or point cloud.
write_glb: Write meshes as a GLB: glTF 2.0’s single-file binary form.
write_obj: Write meshes as Wavefront OBJ.
write_ply: Write one mesh as ASCII PLY.
write_ply_binary: Write a cloud, or a mesh over it, as binary little-endian PLY.
write_vrml: Write meshes as VRML 97.