remove nearest_neighbors

Summary: knn is more general and faster than the nearest_neighbor code, so remove the latter.

Reviewed By: gkioxari

Differential Revision: D20816424

fbshipit-source-id: 75d6c44d17180752d0c9859814bbdf7892558158

pytorch3d/csrc/ext.cpp

@@ -7,7 +7,6 @@
 #include "face_areas_normals/face_areas_normals.h"
 #include "gather_scatter/gather_scatter.h"
 #include "knn/knn.h"
-#include "nearest_neighbor_points/nearest_neighbor_points.h"
 #include "packed_to_padded_tensor/packed_to_padded_tensor.h"
 #include "point_mesh/point_mesh_edge.h"
 #include "point_mesh/point_mesh_face.h"
@@ -21,7 +20,6 @@ PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
   m.def("padded_to_packed", &PaddedToPacked);
   m.def("knn_points_idx", &KNearestNeighborIdx);
   m.def("knn_points_backward", &KNearestNeighborBackward);
-  m.def("nn_points_idx", &NearestNeighborIdx);
   m.def("gather_scatter", &gather_scatter);
   m.def("rasterize_points", &RasterizePoints);
   m.def("rasterize_points_backward", &RasterizePointsBackward);

pytorch3d/csrc/nearest_neighbor_points/nearest_neighbors_points_cpu.cpp

@@ -1,38 +0,0 @@
-// Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.
-
-#include <torch/extension.h>
-
-at::Tensor NearestNeighborIdxCpu(at::Tensor p1, at::Tensor p2) {
-  const int N = p1.size(0);
-  const int P1 = p1.size(1);
-  const int D = p1.size(2);
-  const int P2 = p2.size(1);
-
-  auto long_opts = p1.options().dtype(torch::kInt64);
-  torch::Tensor out = torch::empty({N, P1}, long_opts);
-
-  auto p1_a = p1.accessor<float, 3>();
-  auto p2_a = p2.accessor<float, 3>();
-  auto out_a = out.accessor<int64_t, 2>();
-
-  for (int n = 0; n < N; ++n) {
-    for (int i1 = 0; i1 < P1; ++i1) {
-      // TODO: support other floating-point types?
-      float min_dist = -1;
-      int64_t min_idx = -1;
-      for (int i2 = 0; i2 < P2; ++i2) {
-        float dist = 0;
-        for (int d = 0; d < D; ++d) {
-          float diff = p1_a[n][i1][d] - p2_a[n][i2][d];
-          dist += diff * diff;
-        }
-        if (min_dist == -1 || dist < min_dist) {
-          min_dist = dist;
-          min_idx = i2;
-        }
-      }
-      out_a[n][i1] = min_idx;
-    }
-  }
-  return out;
-}

pytorch3d/ops/__init__.py

@@ -5,7 +5,6 @@ from .cubify import cubify
 from .graph_conv import GraphConv
 from .knn import knn_gather, knn_points
 from .mesh_face_areas_normals import mesh_face_areas_normals
-from .nearest_neighbor_points import nn_points_idx
 from .packed_to_padded import packed_to_padded, padded_to_packed
 from .points_alignment import corresponding_points_alignment
 from .sample_points_from_meshes import sample_points_from_meshes

pytorch3d/ops/nearest_neighbor_points.py

@@ -1,43 +0,0 @@
-# Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.
-
-
-import torch
-from pytorch3d import _C
-
-
-def nn_points_idx(p1, p2, p2_normals=None) -> torch.Tensor:
-    """
-    Compute the coordinates of nearest neighbors in pointcloud p2 to points in p1.
-    Args:
-        p1: FloatTensor of shape (N, P1, D) giving a batch of pointclouds each
-            containing P1 points of dimension D.
-        p2: FloatTensor of shape (N, P2, D) giving a batch of pointclouds each
-            containing P2 points of dimension D.
-        p2_normals: [optional] FloatTensor of shape (N, P2, D) giving
-                   normals for p2. Default: None.
-
-    Returns:
-        3-element tuple containing
-
-        - **p1_nn_points**: FloatTensor of shape (N, P1, D) where
-          p1_neighbors[n, i] is the point in p2[n] which is
-          the nearest neighbor to p1[n, i].
-        - **p1_nn_idx**: LongTensor of shape (N, P1) giving the indices of
-          the neighbors.
-        - **p1_nn_normals**: Normal vectors for each point in p1_neighbors;
-          only returned if p2_normals is passed
-          else return [].
-    """
-    N, P1, D = p1.shape
-    with torch.no_grad():
-        p1_nn_idx = _C.nn_points_idx(p1.contiguous(), p2.contiguous())  # (N, P1)
-    p1_nn_idx_expanded = p1_nn_idx.view(N, P1, 1).expand(N, P1, D)
-    p1_nn_points = p2.gather(1, p1_nn_idx_expanded)
-    if p2_normals is None:
-        p1_nn_normals = []
-    else:
-        if p2_normals.shape != p2.shape:
-            raise ValueError("p2_normals has incorrect shape.")
-        p1_nn_normals = p2_normals.gather(1, p1_nn_idx_expanded)
-
-    return p1_nn_points, p1_nn_idx, p1_nn_normals