Root motion and movement

Contract

1. Verify the source asset has an animated root bone and Enable Root Motion is set.
2. Choose Root Motion Root Lock: reference pose, animation first frame, or zero, based on the asset.
3. In AnimBP Class Defaults choose the intended Root Motion Mode. For network-oriented montage root motion, use Root Motion from Montages Only.
4. Decide how Character Movement mode handles vertical displacement. Walking/Falling apply movement physics differently from Flying.
5. Test capsule/mesh alignment, collision, slopes, stairs, interruption, correction, and blend-out.

Root motion moves the collision-owning character through the movement system; do not separately add the same displacement in gameplay code. Conversely, in-place actions need code-driven movement when displacement matters.

Section/cancel hazards

• Jumping into a Section can skip root displacement that the following frames assume occurred.
• Interrupting a lunge must leave capsule and mesh aligned and define remaining momentum.
• Scaling montage play rate changes displacement timing and gameplay windows.
• Child Montage replacements may preserve timeline length while changing actual root trajectory.
• Root Motion modes move AnimGraph work to the Game Thread; profile target characters.

For directional or target-aligned actions, use motion/rotation warping only after the source root, target transform, sync points, and maximum allowed warp are explicit. Gameplay collision and target validity remain authoritative.