device-independent units, which results in the best possible rasterization on raster devices. From a 3-D perspective, rendering shadows is also much more realistic with vector graphics, as shadows can be abstracted into the rays of light from which they are formed. This allows for photorealistic images and renderings. For example, consider a circle of radius r. The main pieces of information a program needs in order to draw this circle are an indication that what is to be drawn is a circle the radius r the location of the center point of the circle stroke line style and color (possibly transparent) fill style and color (possibly transparent) Vector formats are not always appropriate in graphics work and also have numerous disadvantages. For example, devices such as cameras and scanners produce essentially continuous-tone raster graphics that are impractical to convert into vectors, and so for this type of work, an image editor will operate on the pixels rather than on drawing objects defined by mathematical expressions. Comprehensive graphics tools will combine images from vector and raster sources, and may provide editing tools for both, since some parts of an image could come from a camera source, and others could have been drawn using vector tools. Some authors have criticized the term vector graphics as being confusing. In particular, vector graphics does not simply refer to graphics described by Euclidean vectors. Some authors have proposed to use object-oriented graphics instead. However this term can also be confusing as it can be read as any kind of graphics implemented using object-oriented programming. Vector operations Vector graphics editors typically allow translation, rotation, mirroring, stretching, skewing, affine transformations, changing of z-order (loosely, what's in front of what) and combination of primitives into more complex objects. More sophisticated transformations include set operations on closed shapes (union, difference, intersection, etc.). In SVG, the composition operations are based on alpha composition. Vector graphics are ideal for simple or composite drawings that need to be device-independent, or do not need to achieve photo-realism. For example, the PostScript and PDF page description languages use a vector graphics model. See also Animation Anti-Grain Geometry Cairo (graphics) Comparison of vector graphics editors Comparison of graphics file formats Computer-aided design Direct2D Illustration Javascript graphics library Raster to vector Raster graphics Resolution independence Turtle graphics Vector game Vector graphics file formats Vector monitor Vector packs Vexel Wire frame model 3D modeling Notes References External