message: Enable device to host copy for BVHs
diff: @@ -596,6 +596,20 @@ private:
  cudaMemcpyHostToDevice
  );
  }
  +
  + template <typename DstVector, typename T>
  + void copy(DstVector& dst, thrust::device_vector<T> const& src)
  + {
  + // Trivial copy. See copy(device_vector, host_vector)
  + dst.resize(src.size());
  +
  + cudaMemcpy(
  + dst.data(),
  + thrust::raw_pointer_cast(src.data()),
  + sizeof(T) * src.size(),
  + cudaMemcpyDeviceToHost
  + );
  + }
  #endif
  };
  