minkowski_difference_xy

compas_model.geometry.minkowski_difference_xy(A, B)

Compute the Minkowski difference of convex polygons A and B in the XY plane.

Parameters:

Acompas.geometry.Polygon

The first polygon.

Bcompas.geometry.Polygon

The second polygon.

Returns:

compas.geometry.Polygon

The polygon representing the difference as the sum of A and -B.

Warning

Currently only convex polygons are supported.

See also

compas_model.algorithms.is_collision_poly_poly_xy()

Notes

The Minkwoski “difference” of two polygons A and B, can be formulated as the Minkowski sum of A and inverted B: A + (-B). [1]

A useful application of the Minkowski difference of two convex polygons A and B is collision detection. If the origin (0, 0) is contained in the difference polygon A + (-B), then a collision between A and B exists.

References

[1]

https://en.wikipedia.org/wiki/Minkowski_addition

Examples

>>> from compas.geometry import Polygon
>>> from compas.geometry import is_point_in_convex_polygon_xy
>>> from compas_model.geometry import minkowski_difference_xy

>>> A = Polygon.from_rectangle([1, 0, 0], 1, 1)
>>> B = Polygon.from_sides_and_radius_xy(5, 1).translated([2.5, 1, 0])
>>> C = minkowski_difference_xy(A, B)

>>> is_point_in_convex_polygon_xy([0, 0, 0], C)
True