UE 5.7 AnimBP LookAt with Transform (Modify) Bone — head/neck twist & wrong direction, can’t get stable “fixated” look at target

Development Programming & Scripting
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Hi everyone,
I’m implementing a LookAt system for my Follow AI in Unreal Engine 5.7. Requirements:

  • When one FollowAI is within a certain range of another, it should look at the other AI.

  • Head should be fixated/locked to the target while LookAt is active (idle head motion should not override it).

  • The rest of the body should continue playing idle/locomotion normally.

Current Approach

I’m doing LookAt in the Animation Blueprint using Transform (Modify) Bone.

Event Graph math:

  • Start: Get Socket Location("head")

  • Target: LookAtTarget.GetActorLocation + (0,0,120) (face height offset)

  • LookAtRot = Find Look At Rotation(Start, Target)

  • ActorRot = Get Actor Rotation(Self)

  • Relative rotation:

    • PitchDiff = LookAtPitch - ActorPitch

    • YawDiff = LookAtYaw - ActorYaw

    • Roll = 0

  • Clamp:

    • Pitch ~ (-30..30)

    • Yaw ~ (-70..70)

  • Make Rotator(PitchClamped, YawClamped, 0)

  • Smooth with RInterpTo before sending to AnimGraph

AnimGraph:

  • Use Cached Pose (MainState) → Local To Component → Transform (Modify) Bone (neck/head) → Component To Local → output

Attempts & Issues

  1. LookAt Node (AnimGraph)

    • Tried LookAt node with Layered Blend per Bone / Blend Poses by Bool

    • Problem: head sometimes stuck / not resetting; blend issues and deformations

  2. Transform (Modify) Bone — head

    • Bone: head / Rotation Mode: Replace Existing / Component Space

    • Problem: head follows target but deforms/tilts weirdly

  3. Layered Blend per Bone

    • Separate LookAtPose, blend only neck/head chain

    • Problem: idle head movement sometimes overrides lock

  4. Transform (Modify) Bone — neck

    • Bone: neck_01 / Replace/Add settings

    • Problem: more deformation; upper body twist

  5. Add to Existing (Bone Space)

    • Bone: neck_01

    • Problem: reduces deformation, but idle head motion still affects look

  6. Chained ModifyBone nodes (neck + head)

    • Replace Existing: locks head but sometimes twists wrong direction / looks backward

  7. Axis remap attempt

    • Tried mapping yaw → roll (MakeRotator(Pitch, Roll=Yaw, Yaw=0))

    • Problem: still collapses or flips

Questions / Help Needed

Looking for the correct, stable way to implement LookAt using Transform (Modify) Bone without deformation or rotation flipping. Specifically:

  • Best rotation space (Component vs Bone) for Replace Existing?

  • Best way to convert world LookAt rotation into ModifyBone rotation without missing nodes?

  • How to normalize yaw/pitch to avoid ±180 flipping (manual or BP method)?

  • Recommended bone chain setup (neck + head split) for stability?