How-To: Hit Zones

Goal: report which part of a target was struck, so head shots and weak points can be worth something. Optional - skip it if every hit on an actor is equal.

Prerequisites

Quick Start, so you have a working attack to test against.

The plugin assigns no meaning to a zone

A hit zone is a FGameplayTag on the impact. What a head shot is worth is your damage execution's decision, not this plugin's.

1. Choose a mechanism

Mechanism	Use when	Cost
`UCrimsonHitZonePhysicalMaterial`	Your project authors physics assets. Preferred	One physical material asset per zone. No per-actor setup, and it survives skeleton renames
`UCrimsonHurtboxComponent`	Authoring physical materials is impractical	One bone-to-zone map per skeleton, maintained by hand

2a. Physical materials

Right-click in the Content Browser and choose Crimson -> Hit Detection -> Hit Zone Physical Material. Set its Zone Tag, then assign it to the relevant body in the skeletal mesh's Physics Asset. A physics asset already assigns a physical material per body, which is exactly per-zone granularity.

Only swept queries return physical materials

Crimson Selection: Socket Sweep, Crimson Selection: Actor Sweep and Crimson Selection: Trace request physical materials. The Targeting System's own AOE and Trace tasks do not, so a preset built on those falls back to the hurtbox component - and an AOE overlap reports no bone name either, so it resolves no zone at all. Crimson Selection: Area overlaps too, so the same limit applies to it.

2b. Hurtbox component

Add a Crimson Hurtbox component to the target and fill in Bone Zones. Lookup walks up the skeleton, so mapping head also covers every bone parented under it - which matters because physics bodies routinely report a child bone such as a jaw rather than the one you mapped. Default Zone Tag covers everything unmapped.

Verify

Run Crimson.HitDetection.Debug 1 and strike the zone. An impact carrying a zone tag draws in amber rather than green, so you can see zone resolution working without reading a log.

3. Read the zone

Break the Report from On Hit Targets Resolved, break an entry of its Impacts array, and read Zone Tag. To resolve a zone from a hit result you obtained elsewhere, use the Resolve Hit Zone Tag node.

Verify

Strike a mapped bone and an unmapped one, and confirm the zone tag differs. Resolution order is physical material first, hurtbox second, invalid tag if the target declares no zones.

Turning it off

Untick Resolve Hit Zones on a profile whose attacks never care about zones. It costs nothing when targets declare none, so this is a clarity setting rather than a performance one.