In Maya, a directed acyclic graph (DAG), defines elements such as the position, orientation, and scale of geometry. The DAG is composed of two types of DAG nodes, transforms and shapes.

在Maya里，幾何體的位置，方向和縮放元素是由DAG（有向無(wú)環(huán)圖）定義的。DAG有兩類(lèi)DAG節(jié)點(diǎn)組成：transform節(jié)點(diǎn)和shape節(jié)點(diǎn)。

Transform nodes—Maintain transformation information (position, rotation, scale, etc.) as well as parenting information. For example, if you model a hand, you would like to apply a single transformation to rotate the palm and fingers, rather than rotating each individually—in this case the palm and fingers would share a common parent transformation node.

Transforms節(jié)點(diǎn)包含了變換信息（位置，旋轉(zhuǎn)，縮放等等）以及父子級(jí)信息。例如，如果你想做一只手，你更希望用一個(gè)旋轉(zhuǎn)信息控制手掌和手指，而不是讓他們各自單獨(dú)移動(dòng)。在這種情況下，手掌和手指會(huì)共享同一個(gè)父級(jí)transform節(jié)點(diǎn)。

Shape nodes—Reference geometry and do not provide parenting or transformation information.

Shape節(jié)點(diǎn)是個(gè)參考幾何體，并且不提供父子級(jí)信息和變換信息。

In the simplest case, the DAG describes how an instance of an object is constructed from a piece of geometry. For example, when you create a sphere, you create both a shape node (the sphere) and a transformation node that allows you to specify the sphere’s position, scale, or rotation. The transformation node’s shape node is its child.

在最簡(jiǎn)單的情況下，DAG描述了一個(gè)幾何體是如何組成一個(gè)對(duì)象的實(shí)體的。例如，當(dāng)你創(chuàng)建一個(gè)球的時(shí)候，你同時(shí)創(chuàng)建了一個(gè)shape節(jié)點(diǎn)（球）和一個(gè)transform節(jié)點(diǎn)。transform節(jié)點(diǎn)允許你給球設(shè)定位置，縮放或者旋轉(zhuǎn)角度。transform節(jié)點(diǎn)的shape節(jié)點(diǎn)是它的子級(jí)。