Skip DiffDMC (CUDA arch mismatch on A10G), use marching cubes with adaptive iso-level and bg_fill

patches/triposg/triposg/inference_utils.py

@@ -486,36 +486,26 @@ def flash_extract_geometry(
     del grid_logits
     torch.cuda.empty_cache()
     mesh_v_f = []
+    # Marching cubes on CPU — skip DiffDMC (CUDA arch mismatch on ZeroGPU A10G)
     try:
-        if DiffDMC is not None:
-            print("[TripoSG] Attempting DiffDMC extraction...")
-            # Re-upload with NaN intact so DiffDMC ignores masked cells
-            gl_gpu = torch.from_numpy(grid_logits_cpu).to(device)
-            dmc = DiffDMC(dtype=torch.float32).to(device)
-            sdf = -gl_gpu / octree_resolution
-            sdf = sdf.contiguous()
-            vertices, faces = dmc(sdf, deform=None, return_quads=False, normalize=False)
-            vertices = vertices.detach().cpu().numpy()
-            faces = faces.detach().cpu().numpy()[:, ::-1]
-            vertices = vertices / (2 ** octree_depth) * bbox_size + bbox_min
-            mesh_v_f = (vertices.astype(np.float32), np.ascontiguousarray(faces))
-            print(f"[TripoSG] DiffDMC: {len(vertices)} vertices, {len(faces)} faces")
-            if len(vertices) == 0:
-                raise RuntimeError("DiffDMC returned empty mesh — falling back to marching cubes")
-        else:
-            raise RuntimeError("DiffDMC unavailable — using marching cubes")
+        # Replace NaN/background with min_real - 1 so they're clearly "outside"
+        real_vals = grid_logits_cpu[~np.isnan(grid_logits_cpu)]
+        if len(real_vals) == 0:
+            raise RuntimeError("grid contains no real values (all NaN)")
+        min_real = float(real_vals.min())
+        max_real = float(real_vals.max())
+        print(f"[TripoSG] grid value range: [{min_real:.4f}, {max_real:.4f}], real cells: {len(real_vals)}")
+        bg_fill = min_real - 1.0
+        gl_mc = np.where(np.isnan(grid_logits_cpu), bg_fill, grid_logits_cpu)
+        # Find a valid iso-level — prefer 0.0 but fall back to midpoint
+        iso_level = 0.0 if (min_real < 0.0 < max_real) else (min_real + max_real) * 0.5
+        print(f"[TripoSG] using iso_level={iso_level:.4f}")
+        vertices, faces, normals, _ = measure.marching_cubes(gl_mc, iso_level, method="lewiner")
+        vertices = vertices / (2 ** octree_depth) * bbox_size + bbox_min
+        mesh_v_f = (vertices.astype(np.float32), np.ascontiguousarray(faces))
+        print(f"[TripoSG] marching cubes: {len(vertices)} vertices, {len(faces)} faces")
     except Exception as e:
-        print(f"[TripoSG] DiffDMC path failed ({e}), falling back to marching cubes")
-        torch.cuda.empty_cache()
-        try:
-            # NaN → -1 makes masked/unqueried cells "outside" the isosurface
-            gl_mc = np.nan_to_num(grid_logits_cpu, nan=-1.0)
-            vertices, faces, normals, _ = measure.marching_cubes(gl_mc, 0, method="lewiner")
-            vertices = vertices / (2 ** octree_depth) * bbox_size + bbox_min
-            mesh_v_f = (vertices.astype(np.float32), np.ascontiguousarray(faces))
-            print(f"[TripoSG] marching cubes: {len(vertices)} vertices")
-        except Exception as e2:
-            print(f"[TripoSG] marching cubes also failed: {e2}")
-            mesh_v_f = (None, None)
+        print(f"[TripoSG] marching cubes failed: {e}")
+        mesh_v_f = (None, None)
 
     return [mesh_v_f]