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warp.hash_grid_query_next#

warp.hash_grid_query_next(
query: HashGridQuery,
index: int32,
) → bool#

  • Kernel

Advance a hash grid query to the next candidate neighbor and report whether one was found.

Writes the candidate’s index to index and returns True; returns False once no candidates remain (index is then left unchanged). The index refers to the points the grid was built from, in their original order. Candidates share a nearby grid cell and may lie farther than the query radius, so test the actual distance yourself (see hash_grid_query()). Supports query objects returned by wp.hash_grid_query() for all coordinate precisions.

Parameters:

  • query – The query to advance, from hash_grid_query()

  • index – Output; receives the index of the current candidate neighbor

Returns:

True if another candidate was found (its index written to index), False if the query is exhausted.

Example

@wp.kernel
def count_neighbors(grid_id: wp.uint64, pts: wp.array[wp.vec3], radius: wp.float32, out_count: wp.array[wp.int32]):
    i = wp.tid()
    p = pts[i]
    query = wp.hash_grid_query(grid_id, p, radius)
    index = int(0)
    n = int(0)
    while wp.hash_grid_query_next(query, index):
        if wp.length(p - pts[index]) <= radius:
            n += 1
    out_count[i] = n

points = wp.array([[0,0,0],[0.1,0,0],[0.5,0,0],[2.0,0,0]], dtype=wp.vec3)
grid = wp.HashGrid(dim_x=8, dim_y=8, dim_z=8)
grid.build(points=points, radius=0.3)

out_count = wp.zeros(4, dtype=wp.int32)
wp.launch(count_neighbors, dim=4, inputs=[grid.id, points, 0.3], outputs=[out_count])
print(out_count.numpy())

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warp.hash_grid_query_next(
query: HashGridQuery,
index: int32,
) → bool

  • Kernel

Advance a hash grid query to the next candidate neighbor and report whether one was found (float16 precision).

The float16 overload of hash_grid_query_next(), taking the query returned by the float16 hash_grid_query(). Behavior and usage match the default float32 overload; see it for details and a usage example.

Parameters:

  • query – The query to advance, from hash_grid_query()

  • index – Output; receives the index of the current candidate neighbor

Returns:

True if another candidate was found (its index written to index), False if the query is exhausted.

warp.hash_grid_query_next(
query: HashGridQuery,
index: int32,
) → bool

  • Kernel

Advance a hash grid query to the next candidate neighbor and report whether one was found (float64 precision).

The float64 overload of hash_grid_query_next(), taking the query returned by the float64 hash_grid_query(). Behavior and usage match the default float32 overload; see it for details and a usage example.

Parameters:

  • query – The query to advance, from hash_grid_query()

  • index – Output; receives the index of the current candidate neighbor

Returns:

True if another candidate was found (its index written to index), False if the query is exhausted.