vcti-tree-exporter-mesh 1.0.0

Tree exporter plugins for mesh-schema DataNode trees: PLY, OBJ, and STL writers

vcti-tree-exporter-mesh

Tree exporter plugins for mesh-schema DataNode trees: PLY, OBJ, and STL writers.

Overview

vcti-tree-exporter-mesh is the write side of the mesh package family. It ships three exporters satisfying the vcti-tree-exporter Exporter protocol — PlyExporter (binary little-endian), ObjExporter (text), StlExporter (binary) — that consume a mesh-schema subtree from any tree (typically one a mesh loader such as vcti-fileloader-slim populated) and write its points and triangles to disk. The three formats live in one package deliberately: all are zero-dependency and schema-bound; a format earns its own package only when it brings a heavy dependency.

Installation

pip install vcti-tree-exporter-mesh

In requirements.txt

vcti-tree-exporter-mesh>=1.0.0

In pyproject.toml dependencies

dependencies = [
    "vcti-tree-exporter-mesh>=1.0.0",
]

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Quick Start

Convert a SLIM mesh to STL — loader in, exporter out, the mesh subtree as the hand-off:

from pathlib import Path
from vcti.fileloader.core import DataNode
from vcti.fileloader.slim import SlimLoader
from vcti.tree.core import DictTree
from vcti.tree.exporter.mesh import StlExporter

loader, tree = SlimLoader(), DictTree(root_data=DataNode())
with loader.open(Path("3d.slm")) as handle:
    loader.populate(handle, tree, tree.root_handle)
    StlExporter().export(tree, Path("3d.stl"))

Each exporter finds the tree's (single) mesh subtree by itself; pass root= when the tree holds several. Through the registry, resolution works by id or attribute lookup like the rest of the exporter family:

from vcti.tree.exporter.core import build_registry, get_exporter
from vcti.tree.exporter.mesh import get_exporter_descriptors

registry = build_registry(get_exporter_descriptors())
get_exporter(registry, "ply").export(tree, Path("mesh.ply"), overwrite=True)

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The three formats

Exporter	id	Output	Notes
PlyExporter	ply	binary little-endian PLY	float32 vertices; vertex-only meshes allowed
ObjExporter	obj	Wavefront OBJ text	1-based faces; \n line endings on all platforms
StlExporter	stl	binary STL	computed facet normals; requires a non-empty triangle block

Common behavior: the mesh subtree is validated against the schema before writing (violations raise ExportError with context, never raw numpy errors); 2-D meshes are padded with z = 0; existing files raise FileExistsError unless overwrite=True.

See docs/design.md for the model and boundaries.

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Dependencies

• vcti-tree-exporter — the Exporter protocol and descriptor/registry helpers.
• vcti-mesh-schema — the mesh block schema the writers consume.
• numpy — binary encoding of blocks.