Metrixel 2026.3.0 — Motion Retargeting: one animation library, every character

What's new

Motion Retargeting

Point Metrixel at a source animation, followed by a target character. Every processed asset that has a skeleton will be retargeted; mesh-only assets in-turn are skipped and render exactly as before.

• Sources: FBX, glTF/GLB, and BVH. BVH is the standard motion-capture interchange format. Source clips do not need geometry: an animation-only export without a skin is a valid source, while being a fraction of the size.
• Rigs are identified for you. Auto-Mode: Bone mapping in Metrixel has two settings: Auto and Custom. Auto will read each file's own skeleton, starting with its joint naming. When that returns nothing, Metrixel will use the skeleton's shape - where the limbs branch, which way the knees and feet point, how the chains are proportioned. In-house rigs with unconventional names are mapped without you configuring anything. Auto is done per file, so a target and its sources can be completely different rigs and a batch can mix them freely.
• Custom when you need it, with the file written for you. If a skeleton is a little too unusual to identify, the run will say so in the generation report and Metrixel writes a starter bone map next to the output. It will show the slots to fill in, alongside a listing of that rig's own joint hierarchy. Fill in the names, select it as the character's Custom map, and then do another run.
• Different rest poses are reconciled. For instance, there may be a different definition of "down" between a mocap skeleton standing flat-footed, and a game character on a slight toe. Limbs and feet will follow the source rather than inheriting the target's binding quirks.
• Root motion comes across. The character's stride, path, and vertical motion are transferred and scaled to its own proportions instead of playing on the spot.
• The camera keeps up. The camera is the same for every clip. A retarget run renders one character against many clips, so the framing is taken from the character rather than from each clip: the subject sits at the same on-screen size in every source, and a T-pose renders identically no matter which clip produced it. That consistency is what makes a batch usable as training data as a model sees the pose change, not the scale. The frame carries headroom well past the rest pose, though a few extreme actions can still reach outside it. For travelling clips the camera follows the character, which keeps its feet planted instead of skating.

Batch source folders

Retargeting a library shouldn't mean adding sources one at a time. That is, you can choose the Batch Mode in the Motion Retargeting panel, pick a root folder consisting of the animation files, and all of them will become a source.

With bone mapping set to Auto, the folders will not need further organising. Instead, each of the clip's rig is identified on its own, so a tree mixing skeleton types simply just works. You can also point it at Custom map and that one map applies to everything beneath the folder.

Scriptable end to end

Everything above is available from the command line as well, so dataset preparation can stay workflow-as-code:

metrixel --mode cli --gen_mode batch \
  --input ./characters --output ./dataset \
  --bone_map_target auto \
  --retarget_source_folder ./motions --retarget_source_bone_map auto

Individually chosen sources (`--retarget_sources`), the target rig (`--bone_map_target`), and the master toggle (`--gen_retarget`) are customization flags, and every one of them round-trips through a `.aproj` project file. Pass a path instead of `auto` anywhere a bone map is named to use a Custom map.

Improvements

• Settings panels open up tidily. Every section in the configuration column now starts off collapsed. Expand only what you need.
• Mocap clips start on real motion. Many motion-capture files begin with a calibration pose held before the take. Said frame is now detected and dropped, so a retargeted clip opens mid-motion instead of in a T-pose. Your datasets will not carry a junk first frame.
• The generation report says how each rig was mapped. A new Motion Retargeting section lists every character in the run, whether its skeleton was recognised, inferred, or read from a Custom map, and how many slots resolved. The results will and shall never be a mystery!

Known limitations

• Very unusual skeletons still need a Custom map. Auto needs to find a recognisable biped: a pelvis, a spine, two legs to the feet and two arms to the hands. Quadrupeds, partial rigs and heavily stylised skeletons fall back to Custom, reported per character, with the starter file written for you. Fingers are mapped only when both hands are laid out conventionally; when they are not, hands hold their rest pose rather than being animated wrongly.
• Skeletons that differ in joint count are approximated. Whenm a source chain has more joints than the target's, for instance some mocap skeletons carry a two-joint neck where a game rig has onem, the extra joint's motion is folded in rather than reproduced exactly.
• Retargeted `.glb` files embed the target mesh. Each output is a complete, self-contained character, so a large batch produces substantial output — plan disk accordingly when retargeting hundreds of sources onto a detailed character.
  - Imports beyond 200 MB are still skipped in order to keep processing predictable. There may be a plan in the future to set this yourself.

Pricing

Motion Retargeting is a Professional-plan feature, alongside batch mode, SDF export, TIFF export, and USD animation export. Free and Standard accounts see the controls, and the retarget stage is skipped at runtime with a subscription message; the base renders and exports are unaffected.

Platforms

• Ubuntu 24.04 / RHEL 9 - x86_64 Architecture. Metrixel-2026.3.0-linux-x64.tar.gz.zip Distribution (tarball — bundles EntVista Hub).
• Windows 11 - x86_64 Architecture. .exe Distribution (signed)
• macOS 14 or later - Apple Silicon Architecture. .dmg Distribution (Apple-signed)

Download the latest version from the product page.