fix bugs in generfacto, train_dataparser_outputs.save_dataparser_tran…

…sform and viewer camera on cpu (#3378)

* fix bugs in generfacto, train_dataparser_outputs.save_dataparser_transform and viewer camera on cpu

* fix formating

nerfstudio/engine/trainer.py

@@ -229,10 +229,10 @@ def setup_optimizers(self) -> Optimizers:
     def train(self) -> None:
         """Train the model."""
         assert self.pipeline.datamanager.train_dataset is not None, "Missing DatsetInputs"
-
-        self.pipeline.datamanager.train_dataparser_outputs.save_dataparser_transform(
-            self.base_dir / "dataparser_transforms.json"
-        )
+        if hasattr(self.pipeline.datamanager, "train_dataparser_outputs"):
+            self.pipeline.datamanager.train_dataparser_outputs.save_dataparser_transform(
+                self.base_dir / "dataparser_transforms.json"
+            )
 
         self._init_viewer_state()
         with TimeWriter(writer, EventName.TOTAL_TRAIN_TIME):

nerfstudio/viewer/viewer.py

@@ -458,9 +458,9 @@ def init_scene(
             R = R @ vtf.SO3.from_x_radians(np.pi)
             camera_handle = self.viser_server.scene.add_camera_frustum(
                 name=f"/cameras/camera_{idx:05d}",
-                fov=float(2 * np.arctan(camera.cx / camera.fx[0])),
+                fov=float(2 * np.arctan((camera.cx / camera.fx[0]).cpu())),
                 scale=self.config.camera_frustum_scale,
-                aspect=float(camera.cx[0] / camera.cy[0]),
+                aspect=float((camera.cx[0] / camera.cy[0]).cpu()),
                 image=image_uint8,
                 wxyz=R.wxyz,
                 position=c2w[:3, 3] * VISER_NERFSTUDIO_SCALE_RATIO,