Voxels, volume rendering and volume graphics

Volume rendering, or more generally spoken volume graphics, is a sub-specialty of 3D computer graphics which is concerned with the discrete representation and visualization of objects represented as sampled data in three or more dimensions. A volume/voxel data set is a three-dimensional array of voxels. The term voxel is used to characterize a volume element; it is a generalization of the notion of pixel that stands for a picture element.




Medical CT/NMR scanners are a typical and widely known source of voxel data.


Volume graphics or volume rendering has inherent advantages for applications needing visualization of irregular objects, or where the interior structure is important, or where high level of details and realism is essential - e.g., representations of the human body. Volume graphics is also the choice for CGI manufacturers needing true physics based models of real world phenomena.

While todays widely used 3D computer graphics uses polygonal meshes to represent an object by its surface, only volume graphics uses voxels - 3D or volumetric pixels - as basic element to represent not only the surface but also the entire inner of an object.

Volume graphics visualization today is superior to polygon based 3D graphics in means of image quality and performance when highly complex objects with finest details have to be visualized.


A volume data set is built up from voxels on a regular 3D grid.