ABSTRACT
This chapter presents a separate class of visualization techniques for volumetric scalar fields. It provides the fundamentals of volume visualization techniques and discusses the two main classes of volume visualization techniques, called image-order techniques and object-order techniques. The chapter examines volume visualization techniques, as opposed to their counterparts, which use polygonal geometries. The main power of volume visualization is in the choice of the function that maps an entire set of scalar values, corresponding to the voxels along such a ray, to a single pixel in the resulting 2D image. Choosing the right transfer functions, ray function, and additional visualization parameters to create a good classification is a difficult process that is crucial to obtaining effective visualizations. Volume visualization has been used also to depict other types of data attributes, such as vectors and tensors, and also on different grid types beyond the uniform ones.
