You can use curve anchors to attach AEC objects to the base curve of other AEC objects or linework, such as lines, arcs, circles, mass elements, polylines, roofs, or walls. The movement of an object that is anchored to another object with a curve anchor is constrained by the object to which it is anchored. Curve anchors are best suited for attaching objects to linear objects like lines, arcs, or walls as opposed to grids or layout volumes.