fernandotonon/QtMeshEditor-sam3dbody-onnx

SAM 3D Body (body branch) + MHR — ONNX, for QtMeshEditor

ONNX export of Meta's SAM 3D Body (facebook/sam-3d-body-dinov3, body-only inference path) and of the MHR (Momentum Human Rig) body model, as used by QtMeshEditor for qtmesh body photo.jpg -o body.obj — a human body mesh (18,439 vertices) from ONE photo.

This repository is the standalone model card + mirror. The application downloads from the aggregate repo fernandotonon/QtMeshEditor-models under sam3dbody/; both hold identical files.

Files

file	what	licence
sam3d_backbone.onnx + .onnx.data	DINOv3-ViT-H+/16 backbone, fp32, image [1,3,512,512] (RGB 0..1) → features [1,1280,32,32]	SAM License
sam3d_decoder.onnx	camera-ray conditioning + promptable decoder (6 layers, intermediate pose feedback) + pose/camera heads	SAM License
mhr_body.onnx	MHR body forward (shape [1,45] + model params [1,204] → vertices in cm, joint translations/rotations), no pose correctives, no face model	Apache-2.0 (MHR data)
mhr_faces.i32	MHR body topology, 36,874 triangles, int32 little-endian	Apache-2.0 (MHR data)
mhr_uv.bin	MHR UV layout (int32 nt, nf; float32 texcoords[nt,2]; int32 texcoord_faces[nf,3]) for texturing	Apache-2.0 (MHR data)
LICENSE-SAM.txt, LICENSE-MHR.txt	the licence texts — the SAM License requires a copy to travel with the SAM materials

Provenance and fidelity

Exported by scripts/export-sam3dbody-onnx.py in the QtMeshEditor repository from Meta's checkpoint (the script imports Meta's own package from a local clone; no Meta source files are redistributed). Every graph was checked against Meta's PyTorch run on the same inputs: decoder outputs agree to ~1e-6, backbone to ~2e-5 (fp32 here vs bf16 in Meta's code), MHR to ~1e-4 cm. What is deliberately not reproduced: MHR pose correctives (a 664 MB network; a posed body moves by a mean 2 mm / max 25 mm without it) and the face-expression model (the body head zeroes it).

Pre-processing (person crop, affine warp, CLIFF condition, camera rays) lives in the application (src/BodyFromPhoto/SamBodyPredictor.cpp), not in the graphs.

Licence — read before using

• sam3d_backbone.onnx* and sam3d_decoder.onnx are derivative works of Meta's SAM Materials and are distributed under the SAM License (LICENSE-SAM.txt; Meta Platforms, Last Updated November 19, 2025). It is not an OSI open-source licence: it carries an indemnity clause, a litigation-termination clause, trade-control restrictions and Meta's right to update the terms. By using these files you accept it.
• mhr_body.onnx and mhr_faces.i32 derive from Meta's MHR release data, which is Apache-2.0 (LICENSE-MHR.txt).
• Hosting here follows the maintainer's own reading of the SAM License and is not legal advice.

Not affiliated with or endorsed by Meta.