Exploratories   Scenegraph Builder


This series lets users experiment with, build, study the math of, and play a game based on 3D scene graphs--the hierarchy of transformations used to draw objects in a 3D scene.

The first applet shows how changing the transformations of a scene graph affects the final result and how each transformation affects the space in which child nodes are transformed.

Virtually all 3D packages use scene graphs so it is vital for 3D graphics programmers and serious end users to understand the basic concepts behind them.


The Hierarchy of Transformations applet series was developed for use in an undergraduate computer graphics programming course and is appropriate chiefly for computer science students and anyone programming 3D graphics. It can also help non-programmers better understand commercial 3D software packages.


Users click on a node type (polygon, group, or transformation) and then click in the working area to create new nodes. When a transformation node is selected, users can alter either translation, rotation, or scale along a single axis at a time. In the final applet, specific types of translation nodes are selected from the beginning. The user moves, links, and unlinks nodes with respective mode buttons of the same name and in relevant applets can animate with an "animate" button or control animation with previous, play, stop, and next buttons.