Collision Parameters

Parameters related to collision detection.

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About This Page

This is the complete reference for collision parameters. For the actual setup steps and how to choose shapes, see the Collision Setup guide; for sharing collision across multiple meshes, see Shared Collision.

Collision Types

KawaiiPhysics supports the following 4 collision shapes.

Type	Description
Spherical	Sphere collision
Capsule	Capsule collision
Box	Box collision
Planar	Plane collision

FCollisionLimitBase (Common Properties)

Base properties common to all collision types.

Property	Type	Description
DrivingBone	FBoneReference	Bone that the collision follows
OffsetLocation	FVector	Offset position from bone (Default: ZeroVector)
OffsetRotation	FRotator	Offset rotation from bone (Default: ZeroRotator, Range: -360 to 360)

FSphericalLimit (Sphere Collision)

Adds spherical collision detection.

UPROPERTY(EditAnywhere, Category = "Limits")
TArray<FSphericalLimit> SphericalLimits;

Properties

Name	Type	Default	Description
Radius	float	5.0	Sphere radius (0 or higher)
LimitType	ESphericalLimitType	Outer	Inner/outer limit type

ESphericalLimitType

Value	Description
Inner	Limit to inside the sphere (push bone inside the sphere)
Outer	Limit to outside the sphere (push bone out of the sphere)

FCapsuleLimit (Capsule Collision)

Adds capsule-shaped collision detection.

UPROPERTY(EditAnywhere, Category = "Limits")
TArray<FCapsuleLimit> CapsuleLimits;

Properties

Name	Type	Default	Description
Radius	float	5.0	Capsule radius (0 or higher)
Length	float	10.0	Capsule length (0 or higher)

FBoxLimit (Box Collision)

Adds box-shaped collision detection.

UPROPERTY(EditAnywhere, Category = "Limits")
TArray<FBoxLimit> BoxLimits;

Properties

Name	Type	Default	Description
Extent	FVector	(5.0, 5.0, 5.0)	Box extent (half size for each axis)

FPlanarLimit (Plane Collision)

Adds planar collision detection.

UPROPERTY(EditAnywhere, Category = "Limits")
TArray<FPlanarLimit> PlanarLimits;

Properties

Name	Type	Default	Description
Plane	FPlane	(0, 0, 0, 0)	Plane definition

Loading from Data Asset

LimitsDataAsset

Collision settings can be loaded from a Data Asset. Recommended when you want to reuse settings across different AnimNodes or Animation Blueprints.

UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Limits")
TObjectPtr<UKawaiiPhysicsLimitsDataAsset> LimitsDataAsset;

PhysicsAssetForLimits

Collision settings can also be loaded from a Physics Asset.

UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Limits")
TObjectPtr<UPhysicsAsset> PhysicsAssetForLimits;

World Collision

bAllowWorldCollision

World Collision - Flag to perform collision detection with collisions in the level.

Property	Value
Type	bool
Default	false

warning

Enabling this significantly increases physics processing load.

bIgnoreSelfComponent

Ignore Self Collision - Flag to ignore collisions (PhysicsAsset) owned by the SkeletalMeshComponent in WorldCollision.

Property	Value
Type	bool
Default	true
Edit Condition	bAllowWorldCollision == true

IgnoreBones

Ignore Bones - Setting to ignore collisions (PhysicsAsset) owned by the SkeletalMeshComponent in WorldCollision (specified by bones).

Property	Value
Type	TArray<FBoneReference>
Edit Condition	bIgnoreSelfComponent == false

IgnoreBoneNamePrefix

Ignore Bone Name Prefix - Setting to ignore collisions (PhysicsAsset) owned by the SkeletalMeshComponent in WorldCollision (specified by bone name prefix).

Property	Value
Type	TArray<FName>
Edit Condition	bIgnoreSelfComponent == false

bOverrideCollisionParams

Override Collision Parameters - Set when using custom collision settings instead of SkeletalMeshComponent's collision settings for WorldCollision.

Property	Value
Type	bool
Default	false

Shared Collision

Settings that let multiple KawaiiPhysics nodes share a single set of collision shapes. Collision can be shared across different meshes within the same Actor/ChildActor family. See Shared Collision for details.

bSharedCollisionSource

Publish Collision - Provides this node's collision to KawaiiPhysics nodes in the same attached Actor/ChildActor family (acts as a Source).

Property	Value
Type	bool
Default	false
Category	Limits|Shared Collision

bUseSharedCollision

Use Shared Collision - Uses collision published by Source nodes in the same family (acts as a Target). Mutually exclusive with Source.

Property	Value
Type	bool
Default	false
Edit Condition	!bSharedCollisionSource
Category	Limits|Shared Collision

SharedCollisionGroupTag

Group Tag - A GameplayTag identifying the shared collision group. Both Source and Target use the same tag.

Property	Value
Type	FGameplayTag
Edit Condition	bSharedCollisionSource || bUseSharedCollision
Category	Limits|Shared Collision

tip

To use same-frame collision within one AnimGraph, place the Source node so it evaluates before the Target node.

Collision Source Type

Enum indicating the source of collision settings.

UENUM()
enum class ECollisionSourceType : uint8
{
    AnimNode,      // Use values set in AnimNode
    DataAsset,     // Use values set in DataAsset
    PhysicsAsset,  // Use values set in PhysicsAsset
};

tip

Using Data Assets allows sharing collision settings across multiple AnimNodes and Animation Blueprints.

For more details, see Data Assets.