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warp.mesh_query_point#

warp.mesh_query_point(
id: uint64,
point: vec3f,
max_dist: float32,
) → MeshQueryPoint#

  • Kernel

  • Differentiable

Compute the closest point on the warp.Mesh with identifier id to the given point in space.

The sign of the distance (inside/outside) is determined by casting three axis-aligned rays from point and taking a majority vote over the orientation of the closest hit along each ray; a ray that misses the mesh counts as an outside vote. Classification therefore relies on consistent, outward-facing winding and assumes a watertight mesh, and it is relatively robust but more expensive than mesh_query_point_sign_normal(). Sign classification examines the whole mesh and is not bounded by max_dist, which only limits the returned closest point. See the other mesh_query_point_* functions for alternative sign-determination methods.

Triangles that are degenerate or nearly degenerate relative to their edge lengths are excluded from the closest-point search, so such a face can be skipped even when it satisfies the distance constraint. If every face satisfying the distance constraint is excluded, the query returns no result.

Parameters:

  • id – The mesh identifier

  • point – The query point, in the mesh’s local space

  • max_dist – Maximum allowed distance to the returned closest point. The query returns no result if no face is strictly closer than this distance.

Returns:

A warp.MeshQueryPoint. Check result first (True if a face within max_dist was found), then read sign (< 0 if point is inside the mesh, >= 0 if outside), face (index of the closest face), and the barycentric coordinates u and v of the closest point on that face. Pass face, u and v to mesh_eval_position() to obtain the closest point’s position.

Example

@wp.kernel
def nearest(mesh_id: wp.uint64, p: wp.vec3, out_pos: wp.array[wp.vec3], out_inside: wp.array[wp.int32]):
    res = wp.mesh_query_point(mesh_id, p, 1.0e6)
    if res.result:
        out_pos[0] = wp.mesh_eval_position(mesh_id, res.face, res.u, res.v)
        out_inside[0] = wp.where(res.sign < 0.0, 1, 0)

points = wp.array([[0,0,0],[1,0,0],[1,1,0],[0,1,0],[0,0,1],[1,0,1],[1,1,1],[0,1,1]], dtype=wp.vec3)
indices = wp.array([0,3,2, 0,2,1,  4,5,6, 4,6,7,  0,1,5, 0,5,4,
                    2,3,7, 2,7,6,  0,4,7, 0,7,3,  1,2,6, 1,6,5], dtype=wp.int32)
mesh = wp.Mesh(points=points, indices=indices)

out_pos = wp.zeros(1, dtype=wp.vec3)
out_inside = wp.zeros(1, dtype=wp.int32)
wp.launch(nearest, dim=1, inputs=[mesh.id, wp.vec3(0.5, 0.5, 0.25)], outputs=[out_pos, out_inside])
print(out_pos.numpy()[0], "inside:", bool(out_inside.numpy()[0]))

[0.5 0.5 0. ] inside: True