Update the handling for uninstalled open3d

examples/PointCloud/visualize_pointcloud.py

@@ -3,11 +3,11 @@
 import numpy as np
 import cv2
 import time
+import sys
 try:
     import open3d as o3d
 except ImportError:
-    print("Open3D not installed, to be able to run the example install Open3D with: python3 -m pip install open3d")
-    exit(1)
+    sys.exit("Critical dependency missing: Open3D. Please install it using the command: '{} -m pip install open3d' and then rerun the script.".format(sys.executable))
 
 FPS = 30
 class FPSCounter: