maskEffect.SetUniform( "uImageSize", Vector2(0,0) /*Constrained to actor size*/ );
maskEffect.ApplyConstraint( Constraint::New<Vector2>( maskEffect.GetPropertyIndex("uImageSize"),
maskEffect.SetUniform( "uImageSize", Vector2(0,0) /*Constrained to actor size*/ );
maskEffect.ApplyConstraint( Constraint::New<Vector2>( maskEffect.GetPropertyIndex("uImageSize"),