McNeel Wiki

Cage tools provide a way to deform objects using another object's control points. Generally speaking the goal of cage editing is to control a relatively complex object or objects, in other words objects for which direct point editing is not practical. The controlling object can be a surface, a curve, or a Cage object. Cages have control points in three directions, control objects derived from curves and surfaces have control points exactly as in the curve or surface. 3d Cage objects can be created inside the CageEdit command or they can be created separately using the Cage command and then selected during CageEdit. Curves or surfaces selected as control objects are no longer curves or surfaces though their structure remains the same, they become strictly control objects. The controlling objects as well as the objects being deformed are selected in the CageEdit command.

RegionToEdit option- The region to edit determines the volume of space that will be affected by the cage when it is edited. The default is to edit all of space in the model- that is, the cage will affect its captives equally no matter where they are- in practice this usually means that objects far from the cage will be moved and distorted more than objects close by since the effect goes out radially from the object. There are several options to limit the space that is deformed by the cage- Local means that the control object will deform fully any captives inside or on the control object but the effect will decrease smoothly across the uesr defined falloff distance. Other allows the user to chose a sphere, box or cylinder within which the effect of the cage will be 100%. The effect will tail off smoothly according to the fall off distance.

(Images and example files coming)