Introduction

Five days ago, Hyper3D Rigging landed in the Rodin web app with prompt-editable skeletons. We covered that launch in Hyper3D Rigging Goes Prompt-Editable. Today the same rigger moved off the canvas and into your build scripts. At 13:39 MYT (05:39 UTC, Nov 9), Deemos posted that the Hyper3D Rigging API is now available to everyone. The endpoint is documented and priced, and you can call it with nothing more than a Rodin API key.

This is a closed, paid API rather than open weights. It takes a mesh in and gives a rigged, skinned, optionally animated character back. It's built for the part of the game-asset pipeline everyone hates doing by hand.

What the endpoint actually does

There is one call, POST https://api.hyper3d.com/api/v2/rigging, and it accepts two kinds of input:

  • A Rodin asset. Pass the asset_id of a finished Rodin generation. Geometry and confirmed textures are reused as-is, and the source image is pulled in automatically.
  • Your own model. Upload obj, glb, stl, fbx, usd, usda, usdz or usdc. Embedded materials are dropped, so if you want textures back you also send a reference image.

The interesting knobs:

  • Skeleton templates. auto picks from human, quadruped, bird, dragon and kaiju by looking at your image (or a clay render of your mesh). custom takes either a flat JSON bone hierarchy of up to 256 nodes or a plain-English skeleton_description. That second option is the prompt-editable rig from the web app, now scriptable.
  • Skinning. shell is surface-first and general-purpose. core is tuned for humanoids, with tighter influence for cleaner joints.
  • Animation. Attach up to 10 stock presets such as human_sp/walking or Canine/run, or up to 10 of your own FBX clips (one take each, 25 MiB max).
  • Output. glb, fbx or usdz, with PBR, Shaded, Hybrid, All or None materials.
  • Price. A base rigging job costs 0.5 credits. Credits are reserved when you submit, charged only when packaging succeeds, and released on failure or cancellation.

Pro Tip

The endpoint returns HTTP 201 even when the submit fails. Errors such as API_NO_ACTIVE_SUBSCRIPTION, API_SUBSCRIPTION_PLAN_TOO_LOW or API_INSUFFICIENT_FUNDS come back in the error field of a 201 body. Check that field in your pipeline, not the status code, or a batch job will report success on rigs that never started.

Wire it into your asset pipeline

Here's the docs' showcase flow: upload a humanoid FBX, rig it with humanoid skinning, attach an animation and export FBX.

curl --fail-with-body --request POST 'https://api.hyper3d.com/api/v2/rigging' \
  --header "Authorization: Bearer ${RODIN_API_KEY}" \
  --form 'model=@./model.fbx' \
  --form 'bone_template=human' \
  --form 'skinning_method=core' \
  --form 'material=None' \
  --form 'animation_preset=human_sp/flair' \
  --form 'geometry_file_format=fbx'

For a creature that doesn't fit a preset, switch to a custom skeleton and describe it:

curl --fail-with-body --request POST 'https://api.hyper3d.com/api/v2/rigging' \
  --header "Authorization: Bearer ${RODIN_API_KEY}" \
  --form 'model=@./model.glb' \
  --form 'image=@./reference.png' \
  --form 'bone_template=custom' \
  --form 'skeleton_description=A four-legged lizard with a long segmented tail and two small wings' \
  --form 'material=PBR' \
  --form 'geometry_file_format=glb'

The flow is asynchronous. Keep the uuid and jobs.subscription_key from the response, poll POST /api/v2/status until every job (packaging included) reads Done, then fetch the files with POST /api/v2/download using the uuid as task_uuid.

Why it matters for game devs

Rigging has been the slow step between text- or image-to-3D and a character that actually moves in Unreal, Unity or Godot. Generators have been fast for a while, but rigging and skinning still took someone sitting in Blender. With an API, the whole Rodin chain becomes one script: generate the mesh, pass its asset_id to rigging, attach a walk cycle, and drop an FBX into the engine. And because it accepts uploaded meshes, it also works on assets that never came from Rodin, such as kitbashed NPCs, scanned props or a whole backlog of static monsters.

At 0.5 credits a rig with refunds on failure, it's cheap enough to batch-rig a roster and throw away the misses. Run a few of your ugliest edge cases through auto and custom before you commit a production budget, because hands, tails and wings are where auto-riggers usually show their limits.

—Titus