Effect Lines for Specifying Animation Effects

When we create 2D animations on a desktop computer using programs such as Microsoft PowerPoint or Macromedia Flash, we assign effects to objects and define their parameters, such as their path, speed, and time of movement. To do this, we use conventional interfaces like menus or dialog boxes. However, the motion effects associated with each object are not displayed on the canvas explicitly, so the user-can investigate the properties of each object only by opening a dialog box to see the animations that are associated with the object. Moreover, setting various parameters using menus and dialog boxes is time-consuming because the user must set each parameter individually. We have therefore developed a method that uses an effect line to set each effect and its parameters. Effect lines are a popular technique that is used in comics and cartoons. They depict information on the effects of an object, such as its speed, length of path, and degree of rotation. They enable us to set effects using simple gestures. In addition, the effect lines can be combined. That is, the effects each effect lines have are merged. The feature makes effect lines flexible for the users to create various animations. Effect lines enable the user to recognize animation by displaying the effect lines on each keyframe during on-screen editing. We have developed a prototype animation authoring system. On this system, the user can create various animations with effect lines. We have evaluated the effectiveness of our method as visual input method and pictorial output method, and have discussed about it. The user can set most of "start effect" of PowerPoint by using effect lines