Creating and Editing Maya Nodes - Autodesk Maya

A Maya scene is a system of interconnected nodes that are packets of data about what exists within the world of a Maya scene. The nodes are the building blocks you, as the artist, put together to create the 3D scene and animation that will fnally be rendered for the world to see. So if you can think of the objects in your scene, their motion, and appearance as nodes, think of the Maya interface as the tools and controls you use to connect those nodes. 

The relationship between these nodes is organized by the Dependency Graph, which describes the hierarchical relationship between connected nodes. The interface provides many ways to view the graph, and these methods are described in this chapter.Any given workfow in Maya is much like a route on a city map. There are usually many ways to get to your destination, and some of these make more sense than others depending on where you’re going. In Maya, the best workfow depends on what you’re trying to achieve, and there is usually more than one possible ideal workfow. 

There are many types of nodes in Maya that serve any number of different functions. All the nodes in Maya are considered Dependency Graph (DG) nodes. Let’s say you have a simple cube and you subdivide it once, thus quadrupling the number of faces that make up the cube. The information concerning how the cube has been subdivided is contained within a DG node that is connected to the cube node.A special type of DG node is the Directed Acyclic Graph (DAG) node. These nodes are actually made of two specifc types of connected nodes: transform and shape. The arrangement of DAG nodes consists of a hierarchy in which the shape node is a child of the transform node.
 

Most of the objects you work with in the Maya viewport, such as surface geometry (cubes, spheres, planes, and so on), are DAG nodes.To understand the difference between the transform and shape node types, think of a transform node as describing where an object is located and a shape node as describing what an object is.The simple polygon cube in Figure 1.1 consists of six fat squares attached at the edges to form a box. Each side of the cube is subdivided twice, creating four polygons per side. That basically describes what the object is, and the description of the object would be contained in the shape node. 

This simple polygon cube may be 4.174 centimeters above the grid, rotated 35 degrees on the x-axis, and scaled four times its original size based on the cube’s local x- and y-axes and six times its original size in the cube’s local z-axis. That description would be in the transform node (see Figure 1.1).

Figure 1.1
A shape node describes the shape of an object and how it has been constructed; a transform node describes where the object is located in the scene.

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By Eric Keller with Todd Palamar and Anthony Honn

Copyright © 2010 by Wiley Publishing, Inc., Indianapolis, Indiana