SAM 3D Body: Export Mesh

The README's headline feature - "save as .stl" - is this node. SAM3DBodyExportMesh writes raw mesh geometry to disk with no skeleton or rig attached. If all you want is the shape (for 3D printing, for dropping into a modeling package as reference geometry, for anything that just needs the surface and doesn't care about bones), this is simpler and faster than going through SAM3DBodyExportFBX, which additionally has to build a rig.

How it works

Point it at a mesh_data object and a filename, and it writes the file. That's the entire job - no rendering, no rigging, no Blender in the loop. Compare that to SAM3DBodyExportFBX, which per the pack's credits adapts Blender-based rigging code from ComfyUI-UniRig; this node skips all of that, which is why it's the lighter, faster option when a rig isn't what you're after.

The inputs and outputs that matter

• mesh_data (SAM3D_OUTPUT) - required, the mesh from SAM3DBodyProcess, SAM3DBodyProcessAdvanced, SAM3DBodyAddMeshToSkeleton, or SAM3DBodyLoadMesh.
• filename (default output_mesh.stl) - the default extension tells you the intended format; the pack is built around STL export for this node, matching what the README advertises.

One output: file_path (STRING) - the resolved path to the file that just got written. Feed it into SAM3DBodySelectMesh or SAM3DBodyLoadMesh later if you want to pull the same mesh back into a graph without re-running inference.

How to install it

Bundled with the full pack - via ComfyUI Manager, search SAM3DBody, install, restart. Manual install:

cd ComfyUI/custom_nodes
git clone https://github.com/PozzettiAndrea/ComfyUI-SAM3DBody.git
cd ComfyUI-SAM3DBody
pip install -r requirements.txt --upgrade
python install.py

No separate download for this node - the heavy dependency in this pack (the SAM 3D Body checkpoint, gated behind Hugging Face access approval) lives with LoadSAM3DBodyModel, not here.

Common issues & troubleshooting

File doesn't show up where you expect. A few people on the release thread reported exports landing in a folder relative to where ComfyUI was launched from rather than the standard output directory - if you can't find the file, check file_path in the console/output rather than guessing, and look next to your ComfyUI launch script rather than assuming it's broken.

You wanted the rig too. This node deliberately doesn't export one - that's SAM3DBodyExportFBX. If you're planning to animate or pose the result later in Blender or a game engine, you almost certainly want the FBX export instead of this one.

Mesh geometry looks off in your 3D viewer. That reflects what SAM 3D Body actually reconstructed, not an export bug - check the mesh with SAM3DBodyVisualize or SAM3DBodyGetVertices before assuming the export step introduced a problem.

Nude, textureless STL. Expected. STL as a format doesn't even carry color or texture information - it's geometry only, which happens to match exactly what SAM 3D Body outputs anyway.