Hi mr. King! I'm not quite sure what you mean... The last input from the outline generator? This is the area you want your footprint to have. This amount will be fixed no matter ho you change the shape. Or do you mean CutOffBottom? this is the minimum depth the rectangle is allowed to have,. It is explained in the previous lesson @3.38; https://thinkparametric.com/courses/view-optimization-using-galapagos-for-grasshopper/videos/232 Hope this answers your question, good luck! Best, Arie