All images from Maya 2008 Character Modeling and Animation: Principles and Practices by Tereza Flaxman.

VFXWorld continues excerpting a new series from the Thomson Course Technology book Maya 2008 Character Modeling and Animation. VFXWorld readers will take on the challenge of animating realistic and compelling characters using the latest version of Maya, the powerful 3D graphics and modeling software. Excerpts will show beginning to intermediate animation students and enthusiasts how to create professional quality characters, explaining the full character animation process from pre-production to final full body and facial animation.

Maya offers a diversity of NURBS modeling tools. In this excerpt you will learn how to use two powerful methods for construction surfaces from NURBS curves: the Birail and the Boundary tools.

Understanding the Birail Tool
The Birail tool allows you to create a surface based on three or more curves. This tool sweeps one or more profile curves along two birail curves (path curves).

This tool has three options:

• Birail 1 tool. This requires two birail curves and one profile curve (see Figure 1).

• Birail 2 tool. This requires two birail curves and two profile curves (see Figure 2).

• Birail 3+ tool. This requires three birail curves and two profile curves (see Figure 3).

To create a birail geometry, you need to create three or more curves that must intersect.

[Figure 1] Birail 1 rail and profile curves.

1. Open a new scene.

2. Select Create > CV Curve Tool.

3. In the Front view, create three curves as shown in Figure 4.

4. Look at the curves in the perspective, and make sure that the vertical curve intersects with the two horizontal ones.