Context-free spheres: A new method for rapid CPK image generation

Thomas C. Palmer, Frederick H. Hausheer

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


A new algorithm for rendering CPK images of molecules is presented. The algorithm is based on the observation that (given certain assumptions) the appearance of a sphere representing an atom is independent of the atom's position or orientation. For example, the size of a sphere's projection on the viewing plane is independent of its distance from the viewing plane. The shading of a sphere is dependent only on lighting parameters that are identical for each atom type. This algorithm takes advantage of this observation by precomputing a template for each unique atom type and stamping these into the image with appropriate offsets in X, Y and Z. The implementation described herein enables generation of CPK images an order of magnitude faster than previous methods, with little sacrifice in image quality.

Original languageEnglish (US)
Pages (from-to)149-154
Number of pages6
JournalJournal of Molecular Graphics
Issue number3
StatePublished - 1988


  • CPK modeling
  • depth buffer algorithms
  • interactive applications
  • raster graphics

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics


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