QtMeshEditor — Vegetation Part Segmentation

Model

• Input: a sampled point cloud float32 [1, N, 3] (normalised to a centred unit box; +Y up).
• Output: per-point class logits over 6 channels (unknown, trunk, branch, foliage, root, flower); 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

Evaluation

• Held-out synthetic validation accuracy: 93.3% (v1.1 — a harder big-canopy / drooping-oak distribution; v1.0 scored 93.8% on the narrower set), per-point, unknown masked. Real-world CC0 vegetation packs are the planned next data slice (mined via material/submesh-name labels).
• Per-class recall on held-out synthetic trees (v1.2 → v1.3): branch 0.58 → 0.92, root 0.57 → 0.80, trunk 0.71 → 0.79, foliage 0.94, flower 0.78; overall 0.85 → 0.92.
• Real-world check (stylized oak FBX, huge low canopy + stubby trunk): v1.0 mislabelled ~63k canopy verts as trunk → v1.3 gives trunk 4.5k, branch 16.6k (full skeleton through the canopy), root 0 (this oak models no root — correct), foliage intact. Root/trunk on real meshes stays the hardest class — the durable fix is the planned CC0 real-vegetation data slice.

Reproducing

Versions

• v1.2.0 (current) — root/trunk/branch balance:
  • roots appear in only ~20% of trees (most real tree meshes model no roots — they're underground) and, when present, are thick / buttress-like / strictly ground-hugging (not twig-thin);
  • a new trunk base FLARE is labelled trunk so a widening base isn't read as root;
  • branches are strengthened — more primary branches, sub-branches that thread up into the canopy, and 3× branch sample weight — so the trunk/root tightening doesn't eat branch recall. Net on the real oak: root over-prediction gone (1980→0 for a rootless tree), branch skeleton recovered (3k→16.6k verts), trunk tightened to the real trunk (10k→4.5k). Held-out branch recall 0.58→0.92, root 0.57→0.80, overall 0.85→0.92.
• v1.1.0 — big-canopy robustness: added an oak regime (stubby trunk, canopy 1.1–2.2× larger, foliage drooping down around/below the trunk top with a low skirt) and solid-VOLUME canopy fill (real leaf-card canopies are dense volumes, not the hollow shells v1.0 trained on). Fixes the verified real-world failure where a stylized oak's low canopy was labelled trunk.
• v1.0.0 — initial synthetic-only release (#818 Track B2).