i have set a gradient with a colorramp on a cube , as you can see in the picture. what we see is that the gradient is exactly in the middle of the object. i want to add an offset node. so that the gradient will show up at another point on the object. for example the complete white part would now be in the middle. or the black part would be in the middle , in stead of having the black part all the way to one side now. how can i do this the best way ?