Add Renderer import in inference.py to support enhanced 3D model generation

inference.py

@@ -4,6 +4,8 @@ import zipfile
 import tempfile
 import os
 import nvdiffrast.torch as dr
+from util.renderer import Renderer
+
 
 def generate3d(model, rgb, ccm, device):
     model.renderer = Renderer(tet_grid_size=model.tet_grid_size, camera_angle_num=model.camera_angle_num,