Press the left Ctrl key to enable rotation of the camera around the viewed
   object.
Press the left Shift key to shift the object within the viewing window.
Press the left Alt key to enable zooming.  Push mouse up to zoom out, down to
   zoom in.



'1' selects the default non-textured cube.
'2' selects the point cloud.
'3' selects an LOD cube.  It is red at the nearest LOD, green at the next, and
    blue at the last LOD.
'4' selects a billboarded cube with a y-axis rotation lock.
'5' selects a billboarded cube with x & y axis rotation.
'6' selects a triangle cloud.  Triangles have random alpha if alpha is enabled
'7' selects a dynamically scaling cube



'a' toggles between the alpha-blending modes
'c' toggles z-buffer compare on/off
'd' toggles the dithering mode
'f' toggles between the filtering modes
'g' toggles fog on/off
'p' toggles perspective correction for textures
'q' toggles the screen quad on/off
't' toggles textures on and off
'w' toggles between the wire-frame modes
'z' toggles z-buffer write on/off
