The Box Collider 2D component is a collider for use with 2D physics. Its shape is a rectangle with a defined position, width and height in the local coordinate space of a Sprite. Note that the rectangle is axis-aligned - that is, its edges are parallel to the x or y axes of local space.
|Density||Changing the density here affects the mass of the GameObject’s associated Rigidbody 2D. Set the value to zero and its associated Rigidbody 2D ignores the Collider 2D for all mass calculations, including centre of mass calculations. Note that this option is only available if you have selected Use Auto Mass in an associated Rigidbody 2D component.|
|Material||A physics Material that determines properties of collisions, such as friction and bounce.|
|Is Trigger||Check this box if you want the Box Collider 2D to behave as a trigger.|
|Used by Effector||Check this box if you want the Box Collider 2D to be used by an attached Effector 2D component.|
|Offset||Set the local offset of the Collider 2D geometry.|
|Size||Set the size of the box in local space units.|