BodyPartReactor

BodyPartReactor Inspector

BodyPartReactor is the workhorse that drives offsets on a single bone. You’ll add one component per bone that should flinch—typically Chest, Head, UpperArms, maybe Pelvis.

Add via: Component ▸ Hit Reactions ▸ Body Part Reactor or drag the prefab helper onto the bone in the Hierarchy.

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Inspector Reference

1. References

Field	Description
Bone	The Transform to animate (usually the same object the script is on).

2. Reaction Profile

Field	Default	Description
Profile	None	Assign a ReactionProfile asset that defines timing and strength.
Use Local Hit Direction	✔️	Convert incoming vector into bone local space for more intuitive direction locking. Disable if you want world‑space comparison (rare).
Override On Hit	❌	Off (default): ignore new hits while weight > 0 (prevents jitter on rapid fire). On: every hit resets timer even if still reacting.
Additive	✔️	Add offsets on top of the animation pose. Disable to fully replace animation (useful on props without an Animator).
Auto‑Invert Back Hits	❌	If forward local Z is negative, flip hit direction so reactions always push backwards. Handy when character faces away from camera in 2D sidescrollers.

3. Advanced Blending

Field	Options	Description
Blend Reset Mode	HardReset / ScaledCarryOver	HardReset: weight drops to 0 on new hit.ScaledCarryOver: keep fraction of current weight (good for auto‑fire).
Carry‑Over Scale	0.3	How much weight to preserve when using ScaledCarryOver.
Slow Blend Mode	❌	Multiplies Blend‑In Speed by Slow Blend Multiplier—simulate sluggish reactions on heavy impacts.
Slow Blend Multiplier	0.4	Weight factor (0–1) applied when Slow Blend Mode is active.
Offsets From Current Pose	❌	Calculate offsets relative to current pose instead of bind pose—prevents drift when base animation is already rotated (e.g., leaning).

4. Follow‑Through (optional)

Field	Default	Description
Follow Transforms [ ]	—	Drag extra bones or objects (e.g., shoulder pads, hair bones) that should inherit a fraction of this bone’s reaction.
Follow Rot Weight	0.2	0–1 fraction of rotation offset applied to followers.
Follow Pos Weight	0.1	0–1 fraction of translation offset applied to followers.

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How It Blends

1. React() is called → stores target rotation/position deltas.

2. Each frame in Update() it ramps weight up (Blend‑In) or down (Blend‑Out) based on profile.

3. In LateUpdate() it applies offsets:

   • Additive Off: Lerp/Slerp bone from bind pose to target.

   • Additive On: multiplies current pose by delta. Keeps Animator motion intact.

4. Animator Layer Weight is set to match weight, ensuring your override layer stays in sync.

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Best Practices

• Chest first: Start with a single chest reactor; once tuned, copy component to other bones.

• Carry‑Over for gunfire: Use ScaledCarryOver with a 0.2–0.4 scale to avoid flickering.

• Inertia chains: Let shoulders follow chest, and head follow shoulders for natural delay.

• Disable Translation on feet: Leg rigs often can’t handle additive position offsets—keep them rotation‑only.

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Runtime Tweaks via Code

You can toggle or swap profiles at runtime:

reactor.profile = heavyHit;
reactor.useLocalHitDirection = false; // e.g., for explosion shockwave

Need to disable reactions altogether? Just enabled = false on the component.

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Next Up

See the HitReactionController Inspector to understand how multiple reactors tie back into one character‑level controller.