warp.bvh_query_sphere#

warp.bvh_query_sphere(
id: uint64,
center: vec3f,
radius: float32,
root: int32,
) → _BvhQuerySphere#

  • Kernel

Construct a sphere query against a BVH object.

Iterates over all items whose bounding box overlaps the sphere (exact sphere-AABB squared-distance test). Tangential contact (the nearest point on the AABB surface exactly on the sphere) is included. A negative radius is clamped to zero. This is a tighter broad-phase than padding a query AABB by the radius, since the sphere is inscribed in the padded box. Advance with bvh_query_next().

Parameters:

  • id – The BVH identifier

  • center – The center of the sphere in BVH space

  • radius – The radius of the sphere; negative values are clamped to zero

  • root – The node to begin the query from, or -1 (default) for the BVH’s global root

Returns:

A warp.BvhQuery. It is opaque; pass it to bvh_query_next().

Example

@wp.kernel
def find_items_in_sphere(bvh_id: wp.uint64, center: wp.vec3, radius: float,
                         hits: wp.array[wp.int32]):
    query = wp.bvh_query_sphere(bvh_id, center, radius)
    item = int(0)
    while wp.bvh_query_next(query, item):
        hits[item] = wp.int32(1)

lowers = wp.array([[0, 0, 0], [2, 0, 0]], dtype=wp.vec3)
uppers = wp.array([[1, 1, 1], [3, 1, 1]], dtype=wp.vec3)
bvh = wp.Bvh(lowers=lowers, uppers=uppers)
hits = wp.zeros(2, dtype=wp.int32)
wp.launch(find_items_in_sphere, dim=1,
          inputs=[bvh.id, wp.vec3(0.5, 0.5, 0.5), 0.6, hits])
print(hits.numpy().tolist())

[1, 0]