protected override void OnFrameStarted( object source, FrameEventArgs evt )
{
//base.OnFrameStarted( source, evt );
if ( evt.StopRendering )
return;
color.x += evt.TimeSinceLastFrame * .6f;
if ( color.x > 1 )
color.x = 0;
color.y += evt.TimeSinceLastFrame * .6f;
if ( color.y > 1 )
color.y = 0;
color.z += evt.TimeSinceLastFrame * .6f;
if ( color.z > 1 )
color.z = 0;
}