Update app.py

app.py

@@ -215,6 +215,36 @@ class ReconstructionRunner:
             "source": source,
         }
 
+    def _colmap_gpu_mode(self) -> Tuple[bool, str]:
+        """Determine whether COLMAP should use CUDA acceleration."""
+
+        override = os.environ.get("HF3D_COLMAP_USE_GPU")
+        if override is not None:
+            value = override.strip().lower()
+            if value in {"1", "true", "yes", "on"}:
+                return True, "Forced on via HF3D_COLMAP_USE_GPU"
+            if value in {"0", "false", "no", "off"}:
+                return False, "Disabled via HF3D_COLMAP_USE_GPU"
+
+        if shutil.which("nvidia-smi") is None:
+            return False, "nvidia-smi not found; assuming CPU-only environment"
+
+        try:
+            probe = subprocess.run(
+                ["nvidia-smi"],
+                stdout=subprocess.PIPE,
+                stderr=subprocess.STDOUT,
+                text=True,
+                timeout=5,
+            )
+        except Exception:
+            return False, "nvidia-smi probe failed; defaulting to CPU"
+
+        if probe.returncode != 0:
+            return False, "nvidia-smi returned non-zero exit code; defaulting to CPU"
+
+        return True, "Detected NVIDIA GPU via nvidia-smi"
+
     # ------------------------------------------------------------------
     # COLMAP integration
     # ------------------------------------------------------------------
@@ -229,6 +259,12 @@ class ReconstructionRunner:
         dense_dir = output_dir / "dense"
         sparse_dir.mkdir(exist_ok=True)
 
+        use_gpu, gpu_reason = self._colmap_gpu_mode()
+        logs.append(
+            f"COLMAP GPU acceleration: {'enabled' if use_gpu else 'disabled'} ({gpu_reason})."
+        )
+        gpu_flag = "1" if use_gpu else "0"
+
         commands = [
             (
                 "Feature extraction",
@@ -240,7 +276,7 @@ class ReconstructionRunner:
                     "--image_path",
                     str(images_dir),
                     "--SiftExtraction.use_gpu",
-                    "1",
+                    gpu_flag,
                     "--SiftExtraction.max_image_size",
                     str(max_resolution),
                 ],
@@ -253,7 +289,7 @@ class ReconstructionRunner:
                     "--database_path",
                     str(database_path),
                     "--SiftMatching.use_gpu",
-                    "1",
+                    gpu_flag,
                 ],
             ),
             (