Foundation Actionscript 3.0 Animation: Making Things Move!

Overview

What well cover in this chapter:

• Reaching and dragging single segments

• Dragging multiple segments

• Reaching with multiple segments

• Using the standard inverse kinematics method

• Important formulas in this chapter

In Chapter 13, I covered some of the basics of kinematics and the difference between inverse and forward kinematics. That chapter went into forward kinematics. Now, youre ready for its close relative, inverse kinematics. The movements involved are dragging and reaching.

As with the forward kinematics examples, the examples in this chapter build systems from individual segments. Youll begin with single segments, and then move on to multiple segments. First, Ill show you the simplest method for calculating the various angles and positions . This just approximates measurements using the basic trigonometry youve already seen in action. Finally, Ill briefly cover another method using something called the law of cosines, which can be more accurate at the cost of being more complexthat familiar trade-off.