BBSIK Addon
by Afegor
BBSIK Addon brings inverse kinematics to models in the BBS mod, letting a bone chain be posed by moving its end point.
What it does
Inside the form editor's General section, a user interface lets a model be set up for inverse kinematics. Settings made there are written to the model's config.json, and an IK toggle switches the behavior on or off. Chain locator bones and pole vector constraints can be added to shape how a limb bends.
Three solving algorithms can be selected for a chain: CCD, FABRIK and Constrained-FABRIK. A weight parameter sets how strongly the solver affects each pose keyframe in the replay editor. The author notes that moving a bone close to its pole vector boundary can produce uncontrolled, unstable rotations, and that the mod is an early, largely generated build, so saving the world's models before use is advised. The BBS mod is required, and Fabric API must also be present. BBS CML is optional.
Key features
Inverse kinematics toggle
A switch in the form editor turns inverse kinematics on or off for a model.
Chain locator bones
Locator bones and pole vector constraints can be added to a bone chain to control how it bends.
Solver algorithms
Chains can use CCD, FABRIK or Constrained-FABRIK, chosen per chain.
Pose weight in the replay editor
A weight parameter on pose keyframes sets how strongly the solver influences the pose at that point.
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 2
Optional 1
Use cases
Posing limbs in BBS scenes
A chain such as an arm or leg can be posed by its end point, with the joints following the solver.
Testing addon capabilities
Applying the mod to a copy of a player model lets an author check what the addon can do without touching the original model.
Who it’s for: The mod suits authors who animate models in the BBS mod and want joint chains that follow an end point. Because it is early and the author lists known issues, it fits test worlds and copies of models more than finished projects.
Questions
Does BBSIK Addon need the BBS mod?
Which game versions does BBSIK Addon support?
Is the mod needed on servers?
Should a world be saved before using the mod?
In the catalog
BBSIK Addon is one of 8,499 Technology mods on ModsFinder, and one of 4,201 Technology mods for Fabric. 34,764 mods support Minecraft 1.20.1.
Similar mods
What the author says
An addon for the BBS mod that adds Inverse Kinematics to models. This addon is 99% vibecoded and is in the very early stages of development. Save your world and models before using it. I left my player model along with a mod file that makes it easy to test the addon's capabilities. Current features: - User interface…
Official listing
- Modrinth page
- modrinth.com/mod/bbsik-addon
- Owner
- Afegor
- Published
- 2026-01-10
- Updated on Modrinth
- 2026-01-10
- Facts verified
- 2026-10-15