Update Harmonic embedding in NeRF

Summary: Removed harmonic embedding function from projects/nerf and changed import to be from core pytorch3d.

Reviewed By: patricklabatut

Differential Revision: D33142358

fbshipit-source-id: 3004247d50392dbd04ea72e9cd4bace0dc03606b

Author: nikhilaravi

projects/nerf/nerf/harmonic_embedding.py

@@ -7,9 +7,8 @@
 from typing import Tuple
 
 import torch
-from pytorch3d.renderer import RayBundle, ray_bundle_to_ray_points
+from pytorch3d.renderer import RayBundle, ray_bundle_to_ray_points, HarmonicEmbedding
 
-from .harmonic_embedding import HarmonicEmbedding
 from .linear_with_repeat import LinearWithRepeat