Determining where two polygons intersect is important in rendering complex three-dimensional objects. In this example, you can change the position of the orange triangle to determine if and where it cuts the blue triangle. When the plane of the orange triangle crosses the plane of the blue triangle, black dots appear along the edges of the blue triangle. When you select "show cut points", green spheres appear that show where the orange triangle cuts the blue one. In rendering applications, these points can be used to create new child polygons.