Adding Slope Vertices

To add slope vertices:

1. Select Add Vertices from the Slope menu.
   A red cross will appear and will move along the slope line segments as you move your mouse.
2. Once the red cross is on the location where you want the new vertex, click the left mouse button.
3. Repeat step 2 until you have added all the vertices you want.
4. When you've added all the new vertices, press Enter.