Introduction - If you have any usage issues, please Google them yourself
OPENGL roaming the main picture shows a simple example of the cone, roaming the same methods and modeling software SketchUp 1, look at the various angle cone: keep the middle mouse button, scroll the mouse, you can change the cone angle of 2, conical translation: An Zhao mouse button and Shift, you can easy cone. 3, zoom in and cone: the middle mouse scroll, up narrow, to the great below