Revert "Fix: Bypass C0 multiplication for DC-only SH - directly add 0.5 bias for correct shadow rendering"

This reverts commit 4d552879e0847f94a9a0674c55a44338fe189ac2.

trellis/renderers/gaussian_render.py

@@ -110,20 +110,11 @@ def render(viewpoint_camera, pc : Gaussian, pipe, bg_color : torch.Tensor, scali
     colors_precomp = None
     if override_color is None:
         if pipe.convert_SHs_python:
-            # For TRELLIS: The model outputs zero-centered DC values in range [-X, X] where 0 = gray (0.5 RGB)
-            # Standard eval_sh multiplies by C0=0.28 which compresses the range.
-            # For degree-0 (DC only), we bypass eval_sh and directly add 0.5 to map to [0, 1]
-            if pc.active_sh_degree == 0:
-                # Direct DC to RGB: just add 0.5 bias (no C0 multiplication needed for DC-only)
-                dc = pc.get_features[:, 0, :]  # Shape: [N, 3]
-                colors_precomp = torch.clamp_min(dc + 0.5, 0.0)
-            else:
-                # Higher SH degrees - use standard eval_sh with bias
-                shs_view = pc.get_features.transpose(1, 2).view(-1, 3, (pc.sh_degree+1)**2)
-                dir_pp = (pc.get_xyz - viewpoint_camera.camera_center.repeat(pc.get_features.shape[0], 1))
-                dir_pp_normalized = dir_pp/dir_pp.norm(dim=1, keepdim=True)
-                sh2rgb = eval_sh(pc.active_sh_degree, shs_view, dir_pp_normalized)
-                colors_precomp = torch.clamp_min(sh2rgb + 0.5, 0.0)
+            shs_view = pc.get_features.transpose(1, 2).view(-1, 3, (pc.sh_degree+1)**2)
+            dir_pp = (pc.get_xyz - viewpoint_camera.camera_center.repeat(pc.get_features.shape[0], 1))
+            dir_pp_normalized = dir_pp/dir_pp.norm(dim=1, keepdim=True)
+            sh2rgb = eval_sh(pc.active_sh_degree, shs_view, dir_pp_normalized)
+            colors_precomp = torch.clamp_min(sh2rgb + 0.5, 0.0)
         else:
             shs = pc.get_features