warp.bvh\_query\_sphere
=======================

.. function:: warp._src.lang.bvh_query_sphere(id: uint64, center: vec3f, radius: float32, root: int32) -> _BvhQuerySphere

   .. hlist::
      :columns: 8

      * 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 :func:`bvh_query_next`.
   
   :param id: The BVH identifier
   :param center: The center of the sphere in BVH space
   :param radius: The radius of the sphere; negative values are clamped to zero
   :param root: The node to begin the query from, or -1 (default) for the BVH's global root
   
   :returns: A :class:`warp.BvhQuery`. It is opaque; pass it to :func:`bvh_query_next`.
   
   .. rubric:: Example
   
   .. testcode::
   
       @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())
   
   .. testoutput::
   
       [1, 0]