remove torch from cuda

Summary: Keep using at:: instead of torch:: so we don't need torch/extension.h and can keep other compilers happy.

Reviewed By: patricklabatut

Differential Revision: D31688436

fbshipit-source-id: 1825503da0104acaf1558d17300c02ef663bf538

Author: bottler

pytorch3d/csrc/points_to_volumes/points_to_volumes.cu

@@ -9,10 +9,9 @@
 #include <ATen/ATen.h>
 #include <ATen/cuda/CUDAContext.h>
 #include <c10/cuda/CUDAGuard.h>
-#include <torch/extension.h>
 
-using torch::PackedTensorAccessor64;
-using torch::RestrictPtrTraits;
+using at::PackedTensorAccessor64;
+using at::RestrictPtrTraits;
 
 // A chunk of work is blocksize-many points.
 // There are N clouds in the batch, and P points in each cloud.
@@ -117,12 +116,12 @@ __global__ void PointsToVolumesForwardKernel(
 }
 
 void PointsToVolumesForwardCuda(
-    const torch::Tensor& points_3d,
-    const torch::Tensor& points_features,
-    const torch::Tensor& volume_densities,
-    const torch::Tensor& volume_features,
-    const torch::Tensor& grid_sizes,
-    const torch::Tensor& mask,
+    const at::Tensor& points_3d,
+    const at::Tensor& points_features,
+    const at::Tensor& volume_densities,
+    const at::Tensor& volume_features,
+    const at::Tensor& grid_sizes,
+    const at::Tensor& mask,
     const float point_weight,
     const bool align_corners,
     const bool splat) {
@@ -285,17 +284,17 @@ __global__ void PointsToVolumesBackwardKernel(
 }
 
 void PointsToVolumesBackwardCuda(
-    const torch::Tensor& points_3d,
-    const torch::Tensor& points_features,
-    const torch::Tensor& grid_sizes,
-    const torch::Tensor& mask,
+    const at::Tensor& points_3d,
+    const at::Tensor& points_features,
+    const at::Tensor& grid_sizes,
+    const at::Tensor& mask,
     const float point_weight,
     const bool align_corners,
     const bool splat,
-    const torch::Tensor& grad_volume_densities,
-    const torch::Tensor& grad_volume_features,
-    const torch::Tensor& grad_points_3d,
-    const torch::Tensor& grad_points_features) {
+    const at::Tensor& grad_volume_densities,
+    const at::Tensor& grad_volume_features,
+    const at::Tensor& grad_points_3d,
+    const at::Tensor& grad_points_features) {
   // Check inputs are on the same device
   at::TensorArg points_3d_t{points_3d, "points_3d", 1},
       points_features_t{points_features, "points_features", 2},