Chuyển động ngược sẽ cách mạng hóa phim CS4 Flash của bạn. Nó cho phép bạn hình ảnh động Flash CS4 phim một cách xấp xỉ chuyển động như thật. Khi bạn sinh động với Flash CS4, như chúng ta có trong các chương trước của cuốn sách này, chuyển động là khá hạn chế do các kỹ thuật hình ảnh động được tuyển dụng. | CHAPTER 7 ACHIEVING LIFELIKE MOTION WITH INVERSE KINEMATICS THE ESSENTIAL GUIDE TO FLASH CS4 Inverse kinematics will revolutionize your Flash CS4 movies. It allows you to animation Flash CS4 movies in a way approximating lifelike movement. When you animate with Flash CS4 as we have in the previous chapters of this book the motion is fairly limited due to the animation techniques that are employed. While the standard approach to animation is effective for certain things for example the bug flying in the final exercise in Chapter 6 when it comes to lifelike animation such as a person walking or running the animation can feel stilted. This is where inverse kinematics IK can make your Flash CS4 animations great as opposed to good. To create convincing motion you need to study how objects move. Kinematics is the branch of motion study that considers all aspects of the motion of an object without considering the causes that led to that motion. Inverse kinematics is the study of determining the parameters of a flexible jointed model to reflect desired poses. When you combine physics and Flash you have a system for creating fairly accurate animations without a pure math degree. Usually to take full advantage of kinematics you would utilize a mathematical formula to impose motion restrictions. Take for instance the centripetal force in the orbit of the planets around the sun. These orbital velocities aren t erratic or random they are elliptical and can be calculated precisely. Kinematics is not restricted to the heavenly bodies though it can be applied to everyday objects. Flash CS4 has some tools to help create convincing motion without the need of calculus an abacus or a sundial. You see inverse kinematics daily around you. It uses a system of bones to impose a limitation to object movement. Think about how the bones and tendons in your arms restrict your arms motion. The same thing goes for your legs and other parts of your body. Bones aren t limited to living creatures
