Fix bug: sh render is not correct (#1667)

* Update renderers.py

revise the SH renderer

* Update test_renderers.py

change the test target for sh render

nerfstudio/model_components/renderers.py

@@ -180,7 +180,7 @@ class SHRenderer(nn.Module):
         components = components_from_spherical_harmonics(levels=levels, directions=directions)
 
         rgb = sh * components[..., None, :]  # [..., num_samples, 3, sh_components]
-        rgb = torch.sum(sh, dim=-1) + 0.5  # [..., num_samples, 3]
+        rgb = torch.sum(rgb, dim=-1)  # [..., num_samples, 3]
 
         if self.activation is not None:
             rgb = self.activation(rgb)

tests/model_components/test_renderers.py

@@ -40,7 +40,7 @@ def test_sh_renderer():
     sh_renderer = renderers.SHRenderer()
 
     rgb = sh_renderer(sh=sh, directions=directions, weights=weights)
-    assert torch.max(rgb) > 0.9
+    assert torch.max(rgb) > 0.7
 
 
 def test_acc_renderer():