HybridMaMoMask Export FBX

The whole point of generating motion data instead of video is that it's riggable - you can drop it on a character and re-time, re-pose, and composite it in a real DCC tool. This is the node that makes that happen: it writes the motion from HybridMaMoMask Generate to an .fbx file you can open in Blender, Unity, or Maya. It's the payoff node of the T2M chain, and it's the one that feels almost too easy after all the setup.

How it works

Generating motion is one thing; expressing it as an FBX is a whole other job, because FBX needs a skeleton to hang the animation on. The node cheats smartly: it ships a pre-rigged template character (boy_Rigging_smplx_tex.fbx, about 16MB, included in the pack) whose 22 bones match the model's skeleton, then writes your motion's per-frame joint rotations and root translation onto that rig at 20 fps. The conversion path is worth knowing because it's where the numbers go: the 263-dimension motion gets turned into per-joint rotation matrices via quaternion and continuous-6D conversion, then each frame's transforms are written into the template.

Output lands in ComfyUI/output/hybrid_mamomask/ with a timestamped filename, and the node's UI shows a download link for it. It's an output node, so it's the end of the line.

Inputs that matter

• motion - the HYBRID_MAMOMASK_DATA socket from Generate.
• model - the loader's HYBRID_MAMOMASK_MODEL. It needs this because the motion-processing code (recovering root rotation, converting to rotation matrices) lives in the model repo's utils and common packages. It doesn't re-run inference; it just needs the modules around.
• output_dir (default hybrid_mamomask) - subfolder under ComfyUI/output/.
• filename_prefix (default motion) - the file becomes <prefix><timestamp>.fbx, sanitized to safe characters.

Output is a single fbx_path string - the absolute path to the file on disk.

Installing it

Same pack, same dance:

cd ComfyUI/custom_nodes
git clone https://github.com/Mister-Link/link-comfy-nodes
cd link-comfy-nodes
pip install -r requirements.txt

or ComfyUI Manager → "Link Comfy Nodes", then restart. No extra model downloads for this node beyond what the Loader already fetched - the FBX template ships inside the repo.

Common issues

• "FBX export assets were not found" - the template or exporter didn't come with the install. Usually a partial clone; re-clone or git pull the repo.
• The character's proportions aren't yours - the template is a specific rigged boy character. You're getting its skeleton animated; retargeting to your own character is a Blender/Unity job, not something the node does.
• The file's in ComfyUI/output/ but not where you looked - check the output_dir subfolder, and the returned fbx_path tells you the exact absolute path.
• Behavior changes across updates - the pack's README warns the author changes behavior without warning. If an FBX export suddenly looks different after updating, that's the likely culprit.

Also worth knowing: the node cleans up the sidecar files an FBX export sometimes leaves behind (the .fbm folder and a .png preview), so you don't get orphaned junk next to your export. One export, one file, open it, done.