Colliders

Each physics entity needs at least one collider shape alongside its RigidBody. The collider defines the physical shape used for collision detection.

Collider Types

Collider	Shape	Use Case
BoxCollider	Axis-aligned rectangle	Crates, platforms, walls
CircleCollider	Circle	Balls, coins, rounded objects
CapsuleCollider	Capsule (rectangle with rounded ends)	Characters, pills
SegmentCollider	Line segment	Thin walls, one-way platforms
PolygonCollider	Convex polygon (up to 8 vertices)	Custom convex shapes
ChainCollider	Chain of line segments	Terrain, complex static boundaries

Common Properties

All colliders (except ChainCollider) share these properties:

Property	Type	Default	Description
density	number	1.0	Mass density. Affects total body mass
friction	number	0.6	Surface friction (0 = ice, 1 = rubber)
restitution	number	0.0	Bounciness (0 = no bounce, 1 = full bounce)
isSensor	boolean	false	Trigger zone — detects overlap without physical response
categoryBits	number	1	Collision filter category bits
enabled	boolean	true	Enable/disable the collider

Tip

Set isSensor = true to create a trigger zone that fires sensor events without blocking movement.

BoxCollider

An axis-aligned rectangular collider.

Property	Type	Default	Description
halfExtents	Vec2	{x: 0.5, y: 0.5}	Half-width and half-height in physics units
offset	Vec2	{x: 0, y: 0}	Offset from entity center in physics units
radius	number	0.0	Corner rounding radius. Creates a rounded rectangle when > 0

Plus all common properties.

CircleCollider

A circular collider.

Property	Type	Default	Description
radius	number	0.5	Circle radius in physics units
offset	Vec2	{x: 0, y: 0}	Offset from entity center in physics units

Plus all common properties.

CapsuleCollider

A capsule shape (rectangle with semicircle caps on top and bottom).

Property	Type	Default	Description
radius	number	0.5	Capsule radius in physics units
halfHeight	number	0.5	Half-height of the rectangular center section in physics units
offset	Vec2	{x: 0, y: 0}	Offset from entity center in physics units

Plus all common properties.

Collision Filtering

Collision layers let you control which objects can collide with each other. The system uses 16 named layers with bitmask filtering.

How It Works

Each collider has a categoryBits field that assigns it to a layer. The collision matrix in Settings → Physics → Collision Matrix determines which layers interact.

Property	Type	Default	Description
categoryBits	number	1	Layer this collider belongs to (bitmask, one bit per layer)

Collision occurs when both colliders’ layers are allowed to interact in the collision matrix.

Editor Setup

1. Name your layers in Settings → Physics → Collision Layers (up to 16 layers, e.g., “Player”, “Enemy”, “Ground”, “Projectile”)
2. Configure the matrix in Settings → Physics → Collision Matrix — check which layer pairs should collide
3. Assign layers in the Inspector — each collider’s categoryBits dropdown shows the named layers

Note

Collision layers are configured entirely through the editor settings. The physics plugin reads the layer names and collision matrix from the project config automatically — no code setup is needed.

See Also

• Segment Collider — line segment collider
• Polygon Collider — custom convex polygon collider
• Chain Collider — chain of line segments for terrain
• Events — collision and sensor events