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warp.closest_point_edge_edge#

warp.closest_point_edge_edge(
p1: vec3f,
q1: vec3f,
p2: vec3f,
q2: vec3f,
epsilon: float32,
) → vec3f#

  • Kernel

  • Differentiable

Find the closest points between two edges (line segments) [p1, q1] and [p2, q2].

All four endpoints must be in the same coordinate space.

Parameters:

  • p1 – Start point of the first edge

  • q1 – End point of the first edge

  • p2 – Start point of the second edge

  • q2 – End point of the second edge

  • epsilon – An edge whose squared length is <= epsilon is treated as a single point (degenerate); its barycentric weight is then returned as 0.

Returns:

s in [0, 1] is the barycentric weight of the closest point on the first edge (the point is p1 + s * (q1 - p1)), t in [0, 1] is the barycentric weight on the second edge (p2 + t * (q2 - p2)), and d is the distance between those two closest points.

Return type:

A vec3 (s, t, d)

Example

@wp.kernel
def edge_edge(out: wp.array[wp.vec3]):
    p1, q1 = wp.vec3(0.0, 0.0, 0.0), wp.vec3(1.0, 0.0, 0.0)
    p2, q2 = wp.vec3(0.5, 1.0, 1.0), wp.vec3(0.5, 1.0, -1.0)
    out[0] = wp.closest_point_edge_edge(p1, q1, p2, q2, 1.0e-6)

out = wp.zeros(1, dtype=wp.vec3)
wp.launch(edge_edge, dim=1, inputs=[out])
s, t, d = out.numpy()[0]
print(f"s={s:.1f} t={t:.1f} d={d:.1f}")

s=0.5 t=0.5 d=1.0