[kaib]

More specifically when the user clicks on a specific point on the planet and moves the mouse cursor you want that point to still be under the cursor when the mouse button is released. You can extend this construct outside the central sphere into a camera control that works across the screen and feels very intuitive at any zoom level.

Google "sgi trackball" for some interesting code to point the way.

[callumprentice]

Thank you - I'll look that up.