The VolumeViz primitives can be divided into three general types: slice primitives (geometry based primitives), direct volume rendering primitives and height field rendering primitives. Slice type primitives are explained in Section 1.4, “Slice Rendering” Height field primitives are explained in Section 1.6, “Height Field Rendering” Currently there is only one volume rendering node, SoVolumeRender SoVolumeRender SoVolumeRender , which is explained in this section.