Spacebands are also called "bands in space" or "BiS". A spaceband tends to pull its starting segment toward the point in space during wiggle and other operations. A very short spaceband tends to keep the starting segment at the same spot. Recipes can draw spacebands using precise geometry. The length attribute of a space band is always zero. On a segment-to-segment band, the length attribute gives you the current distance between the endpoints of the band. A spaceband does have a goal length, which can be set and queried like the goal length of a segment-to-segment band.