8

Quad Patch 981

Patch gr ids provide convenient "building material"

for custom surfaces and objects, or for adding

patch surfaces to existing patch objects.

You c an animate the surface of a Patch object using

various modifiers such as the Flex and Morph

modifiers. Control vertices and tangent handles of

a patch surface can be animated with an Editable

Patch modifier.

Surf ace Tool s

The output of the

Surface modifier (page 1–833)

is a Patch object. Patch objects offer a flexible

alternative to mesh and NURBS modeling and

animation.

Quad patch and tri p atch

Editable Patches

You can conv ert a basic patch grid to an

editable

patch object (p age 1–950)

.Theeditablepatch

has a variety of controls that let you directly

manipulate it and its sub-objects. For example, at

the Vertex sub-object level, you can move vertices

or adjust their Bezier handles. Editable patches

let you create surfaces that are less regular, more

free-form than the basic, rectangular patches.

When you convert a patch to an editable patch,

you lose the ability to adjust or animate its creation

parameters.