Welcome

Make every impact matter—no key‑framed flinch animations required.

Welcome to Procedural Hit Reactions

Procedural Hit Reactions is a lightweight runtime layer that makes characters, creatures, and even rigid props twist, recoil, and flinch convincingly when struck by projectiles, melee weapons, or explosions. Because every pose offset is computed in real‑time, you can author zero hit‑reaction animations while still keeping full control over style, strength, and timing through intuitive ScriptableObject profiles.

We're excited to announce that Procedural Hit Reactions 1.1 has been released! This update introduces a range of new features, including an overhauled profiles and body part reactor system, along with many additional customization options.

Please note that the documentation is currently being updated to reflect the changes in this release. We appreciate your patience during this process.

Why another hit‑reaction system?

  • Zero authoring overhead — reactions are generated on‑the‑fly so you can spend your animation budget elsewhere.

  • Modular by design — drop a BodyPartReactor on any bone, reuse ReactionProfiles across rigs, and let the system auto‑wire everything for you.

  • Ultra‑cheap — pure math & transforms, no physics ragdoll or heavyweight IK solvers.

  • Direction‑aware — the punch always pushes back from the incoming hit.

  • Artist‑friendly — tweak curves and axis locks in the Inspector; no code dive required.

Package contents

  • Core runtime

    • HitReactionController.cs — routes hits per character

    • BodyPartReactor.cs — drives offsets on a single bone

    • ReactionProfile.cs — ScriptableObject for timing/strength settings

    • HitReactionTrigger.cs — drag‑and‑go collider helper for bullets & blades

  • Sample assets

    • Fully rigged demo character with ready‑made profiles

    • FPSController.cs, projectile prefab, and demo scene

  • Editor tooling

    • Custom Inspectors & gizmos for faster setup (coming soon)

Looking for the step‑by‑step setup? Head over to Get Started → Running the Demo Scene once you finish this page.

Requirements

Minimum

Unity

2020.3 LTS or newer (tested up to Unity 6)

Render Pipeline

Built‑in, URP, and HDRP supported

Platforms

PC/Mac/Linux, Consoles, Mobile, VR

Tip: Reactions are pure transform offsets—no physics components are required—but Rigidbody colliders help if you need precise hit detection.

Changelog Version 1.1 — May 2025 •ReactionProfile Overhaul: Moved all per-hit options (timing, blend behaviour, hit acceptance, axis-locks) from BodyPartReactor into ReactionProfile

•FollowObjects System: Replaced legacy followTransforms with List<FollowObject> to allow per-object rot/pos weights and also added the ability to have multiple followobjects with separate weights in the BodyPartReactor.

• Inspector Enhancements: Migrate Legacy Settings button to convert v1.0 reactor fields into a new profile asset • Create New Profile button under the Profile header

• Migration Utility: Automatically duplicates and renames profiles when legacy values differ, preserving existing setups

• Added UnityPackages for each render pipeline (builtin,urp,hdrp) so the demois playable on any render pipeline. Version 1.0 — Initial Release

  • Core procedural hit-reaction system

  • Basic BodyPartReactor + HitReactionController

  • HitReactionTrigger for auto-routing projectile impacts

  • Sample FPSController and demo scene included

Quick links

NextGetting Started

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