public DepthOfFieldEffect(Game game, float startFocusDistance, float startFocusRange)
: base(game)
{
pdb = new PoissonDiscBlur(game);
dof = new DepthOfField(game);
dof.FocusDistance = startFocusDistance;
dof.FocusRange = startFocusRange;
AddPostProcess(pdb);
AddPostProcess(dof);
}