ABSTRACT
This chapter introduces data visualization in an informal manner and from the perspective of computer graphics. It discusses the reader should be able to construct a simple visualization example using just a C++ compiler and the OpenGL graphics library. In OpenGL, a large class of transparency-related effects can be achieved by using a special graphics mode called blending. Once blending is enabled, OpenGL will combine the pixels of every drawn primitive, such as polygons or lines, with the current values of the frame buffer at the locations drawn. In OpenGL terminology, the drawn primitive is called the source, whereas the frame buffer the primitive is drawn on is called the destination. The polygon normal can be computed automatically by OpenGL from the polygon vertices. The polygon is assumed to be a flat surface, so its normal is constant.
