Foundation Actionscript Animation

by Peters, Keith

• ISBN13: 9781590595183
• ISBN10: 1590595181
• Format: Paperback
• Copyright: 2005-10-24
• Publisher: Apress

Summary

Sure you can animate using motion tweens, in fact we'll help you do that with our Flash Cartoon Animation book, but isn't there something extra special in making things move with just a few lines of code?In this book Keith Peters guides us through some basic animation theory and then demystifies the math and physics behind creating realistic animation, looking at trigonometry, velocity and acceleration, and bouncing & friction.This book will teach you how to use Flash ActionScript to move the objects in your movies, rather than letting Flashs tween engine do it for you. The benefit of this is smaller, more realistic, more dynamic interactive movies that seem to come alive on your screen. Almost all of the code featured in this book will work fine in either Flash MX 2004 or Flash 8, and with a few minor adjustments, most of it can even be applied to Flash MX.Although the text covers many advanced math and physics concepts, making for very realistic motion, theres no need to worry, even if youre a relative newcomer to programming and the last math class you took was in high school (and even if you barely remember that!). This book first covers everything you need to know to get started: the principles of animation, and the basics of ActionScript, trigonometry, and Flash rendering methods. Youll work your way slowly from using code to move a single object across the screen to creating complex systems that really push Flashs capabilities with topics covered including collision detection, particle attraction, and kinematics. The book concludes with looking at 3D animation techniques, including building a basic 3D engine, 3D lines, fills and solids, and matrix math.Once you come to grips with the ideas presented here, youll find yourself creating all manner of exciting animations and games! Summary of Contents Part I ActionScripted Animation Basics Ch. 1 Basic Animation Concepts Ch. 2 ActionScript Basics for Animation Ch. 3 Trigonometry Ch. 4 Rendering Techniques Part II Basic Motion Ch. 5 Velocity and Acceleration Ch. 6 Bouncing and Friction Ch. 7 User Interaction: Dragging and Throwing Part III Advanced Motion Ch. 8 Easing and Springs Ch. 9 Collision Detection Ch. 10 Bouncing off Angles Ch. 11 Billiard Ball Physics Ch. 12 Particle Attraction Ch. 13 Forward Kinematics Ch. 14 Inverse Kinematics Part IV Three D Ch. 15 A Basic 3D Engine Ch. 16 3D Lines, Fills, Solids Ch. 17 Advanced 3D: Backface Culling and Lighting Ch. 18 Matrix Math Part V Tips and Tricks Ch. 19 Tips and Tricks

Table of Contents

Foreword	xii
About the Author	xiii
About the Technical Reviewer	xiv
About the Cover Image Designer	xv
Acknowledgments	xvi
Introduction	xvii
PART ONE ACTIONSCRIPTED ANIMATION BASICS	1	(98)
Basic Animation Concepts	3	(10)
What is animation?	4	(1)
Frames and motion	5	(2)
Frames as records	6	(1)
Programmed frames	7	(1)
Dynamic vs. static animation	7	(3)
Summary	10	(3)
Basics of ActionScript for Animation	13	(28)
Basic animation	14	(14)
A note on versions	14	(1)
Setup	14	(1)
Looping	15	(4)
Frame loops	19	(1)
Clip events	20	(3)
Flash MX events and event handlers	23	(1)
Listeners	24	(1)
Handlers	25	(2)
Events for animation	27	(1)
Movie clips	28	(4)
Movie clip symbols and instances	29	(1)
Movie clip creation	29	(1)
Duplicating movie clips	29	(1)
Attaching movie clips	29	(3)
Creating empty movie clips	32	(1)
Classes and OOP	32	(4)
A basic class	33	(1)
Constructors	34	(1)
Inheritance	34	(1)
A MovieClip subclass	35	(1)
User interaction	36	(3)
Mouse events	36	(1)
Keyboard events	37	(1)
Mouse position	38	(1)
Key codes	38	(1)
Summary	39	(2)
Trigonometry for Animation	41	(28)
What is trigonometry?	42	(1)
Angles	42	(5)
Radians and degrees	43	(1)
Flash's coordinate system	44	(3)
Triangle sides	47	(1)
Trig functions	47	(6)
Sine	47	(2)
Cosine	49	(1)
Tangent	50	(1)
Arcsine and arccosine	51	(1)
Arctangent	51	(2)
Rotation	53	(2)
Waves	55	(5)
Smooth up and down motion	57	(1)
Linear vertical motion	58	(1)
Pulsing motion	58	(1)
Waves with two angles	59	(1)
Waves with the drawing API	59	(1)
Circles and ellipses	60	(2)
Circular movement	60	(2)
Elliptical movement	62	(1)
Pythagorean Theorem	62	(1)
Distance between two points	63	(2)
Important formulas in this chapter	65	(2)
Summary	67	(2)
Rendering Techniques	69	(30)
Colors in Flash	70	(3)
Using hexadecimal color values	70	(1)
Combining colors	71	(2)
Extracting component colors	73	(1)
The Drawing API	73	(14)
Removing drawing with clear	74	(1)
Setting line appearance with lineStyle	75	(1)
Drawing lines with lineTo and moveTo	75	(2)
Drawing curves with curveTo	77	(1)
Curving through the control point	78	(1)
Creating multiple curves	78	(4)
Creating shapes with beginFill and endFill	82	(1)
Creating gradient fills with beginGradientFill	83	(1)
Specifying the fill type	83	(1)
Setting the colors, alphas, and ratios	83	(1)
Creating the matrix	84	(3)
Color transforms	87	(4)
Changing color with the Color object	87	(1)
Setting a single color with setRGB	87	(1)
Transforming colors with setTransform	88	(1)
Changing colors with the ColorTransform object	89	(2)
Filters	91	(3)
Creating a filter	92	(1)
Animating filters	93	(1)
Bitmap control	94	(3)
Important formulas in this chapter	97	(1)
Summary	98	(1)
PART TWO BASIC MOTION	99	(62)
Velocity and Acceleration	101	(22)
Velocity	102	(7)
Vectors and velocity	102	(2)
Velocity on one axis	104	(1)
Velocity on two axes	105	(1)
Angular velocity	105	(2)
Vector addition	107	(1)
A mouse follower	108	(1)
Velocity extended	108	(1)
Acceleration	109	(11)
Acceleration on one axis	110	(2)
Acceleration on two axes	112	(1)
Gravity as acceleration	113	(2)
Angular acceleration	115	(1)
A spaceship	116	(2)
Ship controls	118	(1)
Thrust	119	(1)
Important formulas in this chapter	120	(1)
Summary	121	(2)
Boundaries and Friction	123	(24)
Environmental boundaries	124	(15)
Setting boundaries	124	(2)
Removing objects	126	(4)
Regenerating objects	130	(2)
Screen wrapping	132	(2)
Bouncing	134	(5)
Friction	139	(5)
Friction, the right way	140	(1)
Friction, the easy way	141	(1)
Friction applied	142	(2)
Important formulas in this chapter	144	(1)
Summary	145	(2)
User Interaction: Moving Objects Around	147	(14)
Pressing and releasing a movie clip	148	(2)
Dragging a movie clip	150	(6)
Dragging with mouseMove	151	(1)
Dragging with startDrag/stopDrag	152	(1)
Combining dragging with motion code	152	(4)
Throwing	156	(3)
Summary	159	(2)
PART THREE ADVANCED MOTION	161	(162)
Easing and Springing	163	(26)
Proportional Motion	164	(1)
Easing	164	(8)
Simple easing	165	(3)
When to stop easing	168	(2)
A moving target	170	(1)
Easing isn't just for motion	171	(1)
Transparency	171	(1)
Rotation	171	(1)
Colors	172	(1)
Advanced easing	172	(1)
Springing	172	(14)
Springing in one dimension	173	(2)
Springing in two dimensions	175	(1)
Springing to a moving target	175	(1)
So where's the spring?	176	(1)
Chaining springs	177	(3)
Springing to multiple targets	180	(2)
Offsetting the target	182	(1)
Attaching multiple objects with springs	183	(3)
Important formulas in this chapter	186	(1)
Summary	187	(2)
Collision Detection	189	(22)
Collision detection methods	190	(1)
Built-in hitTest	190	(6)
Hit testing two movie clips	191	(3)
Hit testing a movie clip and a point	194	(1)
Hit testing with shapeFlag	195	(1)
Summary of hitTest	196	(1)
Distance-based collision detection	196	(6)
Simple distance-based collision detection	197	(2)
Collision-based springing	199	(3)
Multiple-object collision detection strategies	202	(6)
Basic multiple-object collision detection	202	(2)
Multiple-object springing	204	(4)
Important formulas in this chapter	208	(1)
Summary	208	(3)
Coordinate Rotation and Bouncing Off Angles	211	(24)
Simple coordinate rotation	212	(1)
Advanced coordinate rotation	213	(4)
Rotating a single object	214	(1)
Rotating multiple objects	215	(2)
Bouncing off an angle	217	(15)
Performing the rotation	220	(2)
Optimizing the code	222	(2)
Making it dynamic	224	(1)
Fixing the ``falling off the edge'' problem	224	(1)
Hit testing	224	(1)
Bounds checking	225	(1)
Fixing the ``under the line'' problem	226	(2)
Bouncing off multiple angles	228	(4)
Important formulas in this chapter	232	(1)
Summary	232	(3)
Billiard Ball Physics	235	(28)
Mass	236	(1)
Momentum	237	(1)
Conservation of momentum	237	(23)
Conservation of momentum on one axis	239	(2)
Placing the objects	241	(1)
Optimizing the code	242	(1)
Conservation of momentum on two axes	243	(1)
Understanding the theory and strategy	243	(4)
Writing the code	247	(9)
Adding more objects	256	(2)
Solving a potential problem	258	(2)
Important formulas in this chapter	260	(1)
Summary	261	(2)
Particle Attraction and Gravity	263	(18)
Particles	264	(1)
Gravity	265	(5)
Gravitational force	265	(3)
Collision detection and reaction	268	(1)
Orbiting	269	(1)
Springs	270	(8)
Gravity vs. springs	270	(2)
A springy node garden	272	(2)
Nodes with connections	274	(2)
Nodes with mass	276	(2)
Important formulas in this chapter	278	(1)
Summary	278	(3)
Forward Kinematics: Making Things Walk	281	(24)
Introducing forward and inverse kinematics	282	(1)
Getting started programming forward kinematics	283	(3)
Moving one segment	283	(2)
Moving two segments	285	(1)
Automating the process	286	(6)
Building a natural walk cycle	287	(3)
Making it dynamic	290	(2)
Making it really walk	292	(10)
Giving it some space	292	(1)
Adding gravity	293	(1)
Handling the collision	294	(2)
Handling the reaction	296	(2)
Screen wrapping, revisited	298	(4)
Summary	302	(3)
Inverse Kinematics: Dragging and Reaching	305	(18)
Reaching and dragging single segments	306	(2)
Reaching with a single segment	306	(1)
Dragging with a single segment	307	(1)
Dragging multiple segments	308	(2)
Dragging two segments	308	(1)
Dragging more segments	309	(1)
Reaching with multiple segments	310	(7)
Reaching for the mouse	310	(4)
Reaching for an object	314	(2)
Adding some interaction	316	(1)
Using the standard inverse kinematics method	317	(5)
Introducing the law of cosines	318	(2)
ActionScripting the law of cosines	320	(2)
Important formulas in this chapter	322	(1)
Summary	322	(1)
PART FOUR 3D ANIMATION	323	(88)
3D Basics	325	(34)
The third dimension and perspective	326	(6)
The z axis	326	(2)
Perspective	328	(1)
The perspective formula	328	(1)
Perspective in ActionScript	329	(3)
Velocity and acceleration	332	(1)
Bouncing	333	(5)
Single object bouncing	333	(3)
Multiple object bouncing	336	(2)
Z-sorting	338	(1)
Gravity	338	(3)
Wrapping	341	(6)
Easing and springing	347	(3)
Easing	347	(1)
Springing	348	(2)
Coordinate rotation	350	(5)
Collision detection	355	(2)
Important formulas in this chapter	357	(1)
Summary	357	(2)
3D Lines and Fills	359	(28)
Creating points and lines	360	(3)
Making shapes	363	(4)
Creating 3D fills	367	(7)
Using triangles	368	(5)
Defining the triangles' colors	373	(1)
Modeling 3D solids	374	(8)
Modeling a spinning cube	374	(3)
Modeling other shapes	377	(1)
Pyramid	377	(1)
Extruded letter ``A''	378	(2)
Cylinder	380	(2)
Moving 3D solids	382	(3)
Summary	385	(2)
Backface Culling and 3D Lighting	387	(24)
Backface culling	388	(6)
Depth sorting	394	(6)
3D lighting	400	(10)
Summary	410	(1)
PART FIVE ADDITIONAL TECHNIQUES	411	(46)
Matrix Math	413	(14)
Matrix basics	414	(1)
Matrix operations	414	(7)
Matrix addition	415	(1)
Matrix multiplication	416	(1)
Scaling with a matrix	416	(1)
Coordinate rotation with a matrix	417	(1)
Coding with matrices	418	(3)
The Matrix class in Flash 8	421	(4)
Summary	425	(2)
Tips and Tricks	427	(30)
Brownian (random) motion	428	(3)
Random distribution	431	(7)
Square distribution	431	(2)
Circular distribution	433	(2)
Biased distribution	435	(3)
Interval-and timer-based animation	438	(5)
Interval-based animation	439	(2)
Timer-based animation	441	(2)
Collisions between same-mass objects	443	(1)
Integrating sound	444	(3)
Useful formulas	447	(10)
Chapter 3	447	(1)
Chapter 4	448	(1)
Chapter 5	449	(1)
Chapter 6	449	(1)
Chapter 8	450	(2)
Chapter 9	452	(1)
Chapter 10	452	(1)
Chapter 11	453	(1)
Chapter 12	453	(1)
Chapter 14	454	(1)
Chapter 15	454	(3)
Index	457