Kawaii Physics Shared Publisher

Not Officially Released

This feature has not been officially released yet. It is planned for KawaiiPhysics v1.22. Specifications may change during development.

Overview

When hair, clothing, and a cape use separate meshes, changing the wind on each node takes repeated work. Shared Publisher lets you set the common direction and strength once and pass them to each part.

BeforeWind set on each part

AfterOne shared wind setup

Direction and strength come from one Publisher. Hair softness and clothing motion remain adjustable on each Kawaii Physics node.

It can also share Simple World Collision gathering settings and results for nearby walls and props.

Sharing Scope and Publishing Conditions

• Meshes must belong to the same Actor family, identified by following attachment parents, or parent Actors when no attachment parent exists, to a root.
• Provide an always-updated AnimGraph branch for the publisher.

Matching tags alone do not share across families. The Shared Collision available before v1.22 sends hand-authored shapes between nodes and has a different role.

Setup Procedure

1. Place one publisher in the body mesh's Post Process AnimBP, or on an always-updated trunk immediately before Output Pose.
2. Set its Shared Group Tag. The default is KawaiiPhysics.Shared.Default. Use only one publisher per family and tag.
3. On collision consumers, enable Use Simple World Collision, select Shared or Auto for Source, and match Shared Tag.
4. Add Procedural Wind to wind consumers, select Shared or Auto for Wind Source, and match Shared Wind Tag.

Publishing happens during Update. A zero-weight branch or inactive state stops publishing even when the pose is connected. Publisher Enabled defaults to true. When false, it keeps its heartbeat and publishes a disabled state: no collision push-out and zero wind.

Shared and Per-Node Settings

Change you want	Where to tune it
Common wind direction and strength for hair and clothing	The publisher's Shared Wind
Softer hair or a heavier-looking cape	Each Kawaii Physics node's physics settings
A common gathering area and set of nearby collision targets	The publisher's Simple World Collision

Sharing Nearby Collision

Configure the interval, Object Types, radius, convex handling, ground, and SkeletalMesh handling in the publisher's Simple World Collision settings. During sharing, corresponding consumer gather values are ignored. An Auto consumer uses its own values only when it falls back to Local.

Publisher Setting	Default	Purpose
Enabled, inside Simple World Collision	true	Enable collision sharing independently
Gather Scope	ActorFamily	Combine bounds of all meshes participating in the same entry; SkeletalMeshComponent uses the publisher mesh bounds
Gather Interval	0.2 seconds	Gather new targets; 0 gathers every frame
Object Types	Empty	Empty uses WorldStatic and WorldDynamic
Override Gather Radius / Gather Radius	false / 200 cm	Specify a radius instead of the automatic bounds range
Override Collision Channel / Collision Channel	false / Pawn	When disabled, use the owning mesh ObjectType to test Block responses
Gather Family Members	false	Gather participating meshes for mutual collision
Skeletal Mesh Collision	None	None, Bounding Box, or Physics Asset

For mutual collision within the family, enable Gather Family Members, include Pawn in Object Types, and select a suitable Skeletal Mesh Collision mode. Each consumer excludes its own mesh shapes. Targets must also Block the query Collision Channel.

Sharing Wind

The publisher's Shared Wind distributes 13 fields from wind direction through Random Force Period, plus phase clocks and the active gust, ActiveGust. Phase Offset, Seed, Time Scale, Enabled, bone filters, and force space remain consumer settings. Changing only the consumer's shared parameters does not override the publisher during sharing.

With Wind Preset Data Asset and Wind Preset Tag set, initialization and reinitialization apply the selected preset to Shared Wind. Successful publisher application also sets Shared Wind's Enabled=true and TimeScale=1, alongside the eleven preset fields. This differs from the ordinary runtime wind preset API, which preserves those two values. See wind presets for details. These are properties of the publisher's own Shared Wind; applying the preset does not rewrite the consumer's properties with the same names. While sharing, however, the published enabled state and phase clock use the publisher's values.

Consumer Source	Collision without a Publisher	Wind without a Publisher
Local	Gather locally	Compute locally
Shared	No push-out	Continue with local time accumulation
Auto	Fall back to Local	Fall back to Local

A present publisher with Enabled=false differs from an absent publisher. Its disabled state is shared; Auto does not reactivate the feature by switching to Local merely because the publisher is disabled.

Setup and Runtime Control

The Kawaii Physics Shared Publisher Reference covers placement, sharing tags, and Source behavior when a publisher is absent. Use UKawaiiPhysicsLibrary for gameplay-triggered changes and GetRuntimeNodeInfosOnComponent for reading shared state.

Related UE documentation

• Gameplay Tags — Review the tag dictionary and hierarchy; consult each reference for KawaiiPhysics matching rules. (UE 5.8)