Box Collider 2D

A rectangular collision shape.

Size is the box's half-width and half-height. The default 0.5 × 0.5 exactly covers a 1×1 sprite.

Scene file

Saved as a <BoxCollider2D> element inside the entity's <Entity> element. Attributes that are left out keep their default. See Scene Files for how values like vectors, colours and file paths are written.

<BoxCollider2D IsTrigger="false" Layer="1" Mask="65535">
    <PhysicsMaterial Filepath="Physics/Bouncy.physicsmaterial"/>
    <Offset X="0" Y="0"/>
    <Size X="0.5" Y="0.5"/>
</BoxCollider2D>

Name	Where	Type	Default
Offset	child X Y	float, shape offset from the entity's position	0, 0
Size	child X Y	float, half-width and half-height	0.5, 0.5
IsTrigger	attribute	bool, reports overlaps without blocking	false
Layer	attribute	int, bit of the collision layer the collider is on	1 (Default)
Mask	attribute	int, bits of the collision layers it collides with	65535 (everything)
PhysicsMaterial	child Filepath, optional	path to a .physicsmaterial (density, friction, restitution)	built-in defaults

Collider sizes are multiplied by the entity's transform scale. Without a Rigid Body 2D on the same entity, the collider is attached to a body that doesn't respond to forces or gravity, so it acts as a solid obstacle. A Lua Script on the entity can define OnBeginContact(other, normal, point) and OnEndContact(other) to hear about collisions and trigger overlaps.

The shape is built when the game starts, so changing collider properties while it's running has no effect.

Lua scripting

Properties

• Layer (string): Name of the collision layer this collider is on (read-only)
• Mask (table of string): Names of the collision layers this collider collides with (read-only)
• Offset (Vec2): Offset of the shape from the entity's position
• PhysicsMaterial (PhysicsMaterial): Density, friction and restitution of the shape, or nil for the defaults
• Size (Vec2): Half the width and height of the box

Functions

• CollidesWithLayer(): Whether this collider's mask includes the named collision layer