Defines the position of a virtual point adjacent to the start vertex of an edge shape.
An edge shape is comprised of multiple edge (line segments) defined by all its vertices. However, when a collision occurs with the start vertex of the shape then this vertex can be used to form a collision normal, and calculate the collision response. This allows for joining of individual edge shapes to produce a continuous collision surface.
This property is identical to EdgeCollider2D.adjacentStartPoint. It is only used when the shapeType is PhysicsShapeType2D.Edges and useAdjacentStart is true.