Geometry modifiers alter the points of an object. Examples include Bend, Taper, Twist, Spherify, and Wave. Note that points mean different things for different objects. For example, a Bend modifier may be applied to both a Cylinder object and a NURBS curve object. That's because they both have 'points' that can be modified, although the nature of the 'points' is quite different between them. Modifiers that operate on these generic points are said to operate on 'deformable' objects. For more information see Deformable Objects.

Modifiers that only alter the geometry channel can be derived from SimpleMod2 rather than Modifier and have fewer methods to implement. In this case, the base class SimpleMod2 provides default implementations for Modifier::InputType(), Modifier::ChannelsUsed() and Modifier::ChannelsChanged().