How linked animation layers work in Motion

Motion uses linked animation layers as an extension point for character pose sets. They are not required for baseline automatic first-person item held pose.

The base character Animation Blueprint owns the high-level flow. A linked layer class can supply active locomotion poses, aim offsets, skeletal controls, left-hand override, and custom hooks when a project needs a broader item or stance pose set.

Why layers matter

Motion builds on Lyra's modular animation system. The main character graph stays stable, while linked layers swap the active animation set.

This matters because a linked layer affects more than the held object. It can drive the pose content used by the full-body locomotion state machine, aiming, skeletal controls, and custom first-person item hooks.

Runtime relationship

Motion's layer stack uses these assets:

• ABP_Mannequin_Base: main Animation Blueprint for the Motion character mesh.
• ALI_ItemAnimLayers: Animation Layer Interface that defines the layer contract.
• ABP_ItemAnimLayersBase: shared base implementation for item or stance layer Blueprints.
• ABP_UnarmedAnimLayers: default unarmed layer.
• ABP_PistolAnimLayers: built-in pistol layer example.

ABP_Mannequin_Base does not hard-code one locomotion animation set. Its state machine delegates state output to linked layer functions such as idle, start, cycle, stop, pivot, jump, fall, and land.

The main AnimGraph also calls layers for aiming, skeletal controls, left-hand override, first-person item space, and first-person upper body. The default baseline first-person held pose behavior belongs to the automatic held pose overlay path, not to required item movement states on ABP_ItemAnimLayersBase.

Runtime flow

For optional broader pose-set swaps, gameplay selects a MotionNativeFirstPersonItemConfig that has LinkedLayerClass assigned. Custom overlay graph references live in CustomOverlaySettings and do not replace the normal linked-layer class.

If no item config is active, Motion falls back to the unarmed layer or pass-through behavior. If an active item config has no LinkedLayerClass, the automatic held pose overlay can still work without a linked-layer setup warning. If an active custom graph config has no custom overlay layer, overlay validation reports a setup error.

Layer responsibilities

Use linked layers for animation content that changes by stance, item, or presentation mode:

• Locomotion states: idle, start, cycle, stop, pivot, jump, fall, and land pose content.
• Aiming: item or stance aim poses and aim offsets.
• Skeletal controls: hand IK and per-layer skeletal control settings.
• Left-hand override: optional left-hand pose override behavior.
• First-person item space: item-specific helper-space or item-space adjustments.
• First-person upper body: custom upper-body behavior for projects that intentionally route through a layer function.

Use the automatic held pose overlay graph for baseline tag-driven item held pose. Use linked layers when the item needs a broader animation set or integration with the existing layer stack:

• put item-specific helper-space changes in FullBody_FirstPersonItemItemSpace
• keep baseline automatic held pose animation, pitch distribution, and hand IK in the Motion held pose overlay
• override broader locomotion variables when the item needs a different full-body pose set

Do not treat FirstPersonItemIdle, FirstPersonItemMove, or FirstPersonItemSprint as required default held pose states. Project-owned fire, reload, recoil, melee, and equip actions should compose after the baseline held pose overlay when they need to override it.

Next steps

Move from the layer model to setup and runtime reference.

Create and link an animation layerBuild a layer for an item, stance, or presentation mode.First-person item configsUnderstand the native data asset that selects meshes and layer content.MotionAnimInstanceLook up the animation instance state exposed to linked layers.