| --- |
| license: cc-by-4.0 |
| tags: |
| - mesh-segmentation |
| - part-segmentation |
| - point-cloud |
| - building |
| - architecture |
| - onnx |
| - 3d |
| - qtmesheditor |
| library_name: onnx |
| pipeline_tag: other |
| --- |
| |
| # QtMeshEditor — Building Part Segmentation |
|
|
| A point-cloud part-segmentation network (PointNet++-style) that labels each |
| point of a **building** mesh as `wall`, `roof`, `window`, `door`, `chimney`, |
| or `foundation`, exported to **ONNX** for local inference via ONNX Runtime. |
|
|
| One of the category-specialised segmentation models built for |
| **[QtMeshEditor](https://github.com/fernandotonon/QtMeshEditor)** (epic #818, |
| Track B2) — a free, open-source 3D mesh & animation editor. The app |
| auto-detects the mesh category with a companion |
| [point-cloud classifier](https://huggingface.co/fernandotonon/QtMeshEditor-mesh-segmentation-category) |
| and dispatches to this model for buildings; siblings: |
| [body](https://huggingface.co/fernandotonon/QtMeshEditor-mesh-segmentation), |
| [vegetation](https://huggingface.co/fernandotonon/QtMeshEditor-mesh-segmentation-vegetation), |
| [vehicle](https://huggingface.co/fernandotonon/QtMeshEditor-mesh-segmentation-vehicle). |
| Aggregate download source used by the app: |
| [QtMeshEditor-models](https://huggingface.co/fernandotonon/QtMeshEditor-models) |
| (`segment/meshseg_building.onnx`). |
|
|
| ## Model |
|
|
| - **Input:** a sampled point cloud `float32 [1, N, 3]` (normalised to a centred |
| unit box; +Y up). |
| - **Output:** per-point class logits over 7 channels |
| (`unknown, wall, roof, window, door, chimney, foundation`); argmax → label, |
| scattered back to mesh vertices/faces by nearest sampled point. |
| - **Architecture:** shared per-point MLP + two kNN local-aggregation blocks |
| (in-graph `cdist`+`topk`, ONNX-exportable) + a global max-pooled feature; |
| ~0.78 MB. Trained at the app's inference sample size (4096 points). |
|
|
| ## Training data & license |
|
|
| Trained **from scratch, 100% on procedurally generated synthetic buildings we |
| own** (no third-party data at all): parametric houses / towers / huts with |
| gable, pyramid, and flat roofs (triangle/quad surface patches), proud window |
| panes in rows, doors, chimneys, and foundation slabs — labels are exact by |
| construction. Weights released under **CC-BY-4.0**; please credit |
| *QtMeshEditor*. |
|
|
| ## Evaluation |
|
|
| - Held-out synthetic validation accuracy: **86.9%** (per-point, unknown |
| masked). Real-world CC0 building kits are the planned next data slice |
| (mined via submesh/material-name labels). |
|
|
| ## Reproducing |
|
|
| `scripts/export-meshseg-onnx.py --category building` in the QtMeshEditor repo |
| (one-time, offline; the app never runs Python). Strategy + roadmap: |
| `docs/MESH_SEGMENTATION_STRATEGY.md`. |
|
|
| ## Versions |
|
|
| - **v1.0.0** (current) — initial synthetic-only release (#818 Track B2). |
|
|
