Heavy biped
Weight sits in the torso and the tail. A turn needs the tail to counter the pelvis. Digitigrade feet have to meet a slope without sliding. A humanoid foot locker does not cover that.
Unreal Engine 5.8 · Claude-assisted rigging & locomotion suite
A suite of tools for the headache of rigging 150+ creature skeletons.
Unreal's animation tools are built around a single human skeleton: two arms, two legs, upright spine. When a project has 150+ creature models across bipeds, quadrupeds, winged flyers, serpents, swimmers, and floating bodies, nothing shares a rig.
We are building a suite of Unreal Engine 5.8 tools powered by Claude and MCP to automate the work that normally kills a small team: reading raw bone trees, generating IKRig retarget chains, wiring ControlRig full-body IK, and setting up foot placement, slope locking, and locomotion across every body plan.
Four body plans
Each one needs its own chains and ground solve.
Heavy quadruped
Shoulders and hips have to meet the ground separately. A stiff back cannot use a canine spine setup. The footfall pattern has to hold while both ends tilt.
Winged
Ground and air need separate solves. Wings fold clear of the legs on the ground, then bank from turn rate in the air. Takeoff and landing are where foot IK and flight conflict.
Long spine
Two-bone and four-bone limb IK do not apply. The body is one chain. Part of it stays up for the head. The rest has to sit on the terrain instead of clipping through it.
Beyond these four: A full roster also hits aquatic swimmers, floating or gas-based bodies, multi-legged arthropods, and shapes with no legs at all. Retargeting, rigging, full-body IK, and foot placement are still mostly hand-authored today. Spatial 3D rigging is one of the areas where Claude and editor tooling actually need to advance.
Generated chains
The editor dumps the raw skeleton via MCP. Claude classifies the anatomy (spine, jaw, limbs, wings, or tail coils) and sets up the IKRig retarget chains and ControlRig ground solve across the roster without manual editor clicking.
// SkeletalMeshTools.get_bone_names -> IKRig chain mapping { "root": "origin", "pelvis": "waist", "bones": [ "origin", "waist", "spine_01", "spine_02", "spine_03", "spine_04", "spine_05", "spine_06", "spine_07", "spine_08", "head", "upper_jaw", "lower_jaw", "tongue_01", "tongue_02", "tongue_03", "tongue_04", "tongue_05", "tongue_06", "hips", "tail_01", "tail_02", "tail_03", "tail_04", "tail_05", "tail_06", "tail_07", "tail_08", "tail_09", "tail_10", "tail_11", "tail_12", "tail_13" ], "chains": { "UpperSpine": { "startBone": "spine_01", "endBone": "spine_08" }, "HeadLook": { "startBone": "head", "endBone": "upper_jaw" }, "GroundCoil": { "startBone": "hips", "endBone": "tail_13" } } }