fix open3d tensor API access of pointcloud data (#19)

src/lidar_visualizer/datasets/generic.py

@@ -117,7 +117,7 @@ def read_scan_with_intensities(file):
                     intensity = scan.point.intensity.numpy()
                     intensity = intensity / intensity.max()
                     colors = self.cmap(intensity)[:, :, :3].reshape(-1, 3)
-                    return np.asarray(scan.points), colors
+                    return scan.point.positions.numpy(), colors
 
                 # else
                 scan = scan.to_legacy()