Controls which degrees of freedom are allowed for the simulation of this Rigidbody2D.
By default this is set to RigidbodyConstraints2D.None, allowing rotation and movement along all axes.
In some cases, you may want to constrain a Rigidbody2D to only move or rotate along some axes. You can use the bitwise OR operator to combine multiple constraints.
See Also: RigidbodyConstraints2D.