Introduction to Vector Animation

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Vector animation is a term used to refer to animation in which the art or motion is controlled by vectors rather than pixels. Vector animation often allows cleaner, smoother animation because images are displayed and resized using mathematical values instead of stored pixel values. One of the most commonly used vector animation programs was Adobe Flash (formerly Macromedia Flash). Before understanding the science behind vector animation, it's important to know the difference between the two major graphic types: bitmap and vector graphics.

Introduction to Bitmap and Vector Graphics

Many of the image types people are most familiar with consist of a grid of pixels in which each pixel or bit contains information about how the color should be displayed. JPEGs, GIFs, and BMP images, for instance, are all pixel images known as raster or bitmap graphics. These bitmap graphics, therefore, have a fixed resolution or a number of pixels in the grid, measured by pixels per inch (PPI). A bitmap’s resolution limits the graphic’s size as they cannot be resized without losing image quality. Everyone has run into a bitmap that has been blown up until it looks blocky or pixelated.

Vector graphics, on the other hand, consist of paths that are defined by a start and end point. These paths can be anything from a line to a series of lines that create a shape like a square or a circle. Despite the simplistic nature of a vector’s building block, paths can be used to create extremely complex diagrams. Each path object carries its own mathematical statement that defines how the object should be displayed. Some of the most common vector formats include AI (Adobe Illustrator), DXF (AutoCAD DXF), and CGM (Computer Graphics Metafile). Vector graphics can also be found in EPS (Encapsulated PostScript) and PDF (Portable Document Format) formats.

The most important difference between vector and bitmap graphics is that vector graphics are resolution independent, meaning that they are truly scalable. Because vector graphics are not made up of a fixed grid-like bitmap graphics, they can be resized without losing image quality. This makes them ideal for a variety of graphic design applications such as logos, which require the ability to be sized down for something small like a business card or sized up for something as large as a billboard sign.

Vector Animations Basics

While some vector editors (computer programs that compose and edit vector graphics) support animation, the most popular programs for animation creation, like Adobe Flash, are specifically geared for that purpose. While animations can include bitmap graphics, most use only vector-based graphics because as we learned earlier, they scale better and typically take up less space. These vector animations generally have a clean graphic appearance as compared to their alternatives.

Internationally, there are other vector formats and animators. For instance, EVA (Extended Vector Animation) is a web-based vector file format popular in Japan where EVA Animator software is widely used. The primary difference between the EVA format and other vector formats is that they record only the changes in the vector over time rather than recording information per frame. EVA formats also tend to be smaller than their alternatives.