Deformer

A deformer is a type of tool in 3D computer graphics and animation that alters the shape or position of geometry. Deformers modify vertex data or control points, often in a non-destructive way, allowing artists to reshape objects without changing their underlying topology. They are used for posing, shaping, and animation, and can affect a single element or an entire object, depending on how they are configured.

Common categories include free-form deformation, where a lattice or cage surrounds the object and moving its points bends or twists the enclosed geometry; non-linear deformers that apply specific spatial transformations such as bend, twist, taper, bulge, stretch, and shear; lattice deformers that manipulate a grid to influence many vertices; skinning or rig-based deformers where an underlying skeleton or control rigs drive vertex positions through weight maps; and blendshape or morph target deformers, which interpolate between stored target shapes to create facial expressions or other shape changes. Additional deformers operate along curves or curves wrapped around surfaces to produce curve-based warp effects.

Deformers are integral to modeling, rigging, and animation workflows, providing non-destructive methods to adjust shape, posture, or silhouette. They are often stacked or combined with other techniques, such as morphing and skeletal animation, to achieve complex results. Practical use requires attention to topology, deformation artifacts, and performance, as excessive or poorly weighted deformers can distort geometry or slow down playback. The concept of deformation in graphics is closely associated with Free-Form Deformation, introduced in the 1980s, which laid the groundwork for many modern deformation techniques.