Let's say I want to create a long, infinite furrow in a plane... I take one plane, volume and make that the ground... Duplicate this.. I make it very thin horizontally, about the size of 10 feet wide and about 10 feet tall... I assign this infinite plane a negative value... Assign the ground infinite plane a positive value... I take the thin infinite plane and position it just slightly above the ground but extending deep into the ground... I group both of them... I don't get a long furrow that extends infinitely... Is there something I'm doing wrong, or does this not work with infinite planes??