A simple interactive sphere in VTK

*Purpose: Create a simple sphere, users can interact with it.

(Please first follow the VTK installation guide to build VTK from source)






Basic interaction functionalities:

Mouse: zoom, pan, rotate...
'w': wireframe
's': surface rendering
'p': picking - highlight the bounding box of selected object
'+': increase resolution of the sphere
'-': decrease resolution of the sphere
'c': choose a random color for the sphere