POVScript+: a program for model and data visualization using persistence of vision ray-tracing

Macromolecular visualization is hampered by the fragmented set of available programs and the lack of cooperativity among them. The amount of visual information required for robust structural analysis is relatively difficult to generate and rarely allows further high-quality three-dimensional graphic rendering. Here, a modification of MolScript [Kraulis (1991). J. Appl. Cryst. 24, 946-950] is presented which contains the capability of the original MolScript, the ability to carry out a majority of the options available in most other crystallographic visualization packages, as well as several new features of its own. POVScript+ (currently version 1.62) allows anisotropic displacement ellipsoid rendering (read in as a second-rank tensor from a PDB file), electron-density polygonization (in several formats derived from a `marching tetrahedra' approach), volumetric rendering of electron density and GRASP/MSMS surface-map input/output. Finally, POVRay output is supported (via a modified version of PovScript) to generate high-quality renderings that are easily modified for any of a number of purposes (e.g. animations or altered textures). POVScript+ provides a marked increase in the amount of structural and atomic detail possible, while still allowing a straightforward means of generating this information.