Retrieves the boundary points contained in an Anchor with an enabled Bounded2D component.
This is the second part of the two-calls idiom for retrieving boundary points. It is expected for the
positions to be created and with enough capacity to contain the boundary points.
ParameterspositionsThe array that will get populated with the boundary points contained in the Bounded2D component of the Anchor.
Returnstrue if it successfully populates the positions array with the boundary points.
ExceptionsArgumentExceptionThrown when positions has not been created.