@techreport{TR-DCC-95-02,
  number = {DCC-95-02},
  author = {de Figueiredo, Luiz H. and Stolfi, Jorge},
  title = {Adaptive Enumeration of Implicit Surfaces with Affine Arithmetic},
  month = {March},
  year = {1995}, 
  institution = {Department of Computer Science, University of Campinas},
  note = {In English, 16 pages.
    \par\selectlanguage{english}\textbf{Abstract}
      We discuss adaptive enumeration and rendering methods for implicit
      surfaces, using octrees computed with affine arithmetic, a new
      tool for range analysis.  Affine arithmetic is similar to standard
      interval arithmetic, but takes into account correlations between
      operands and sub-formulas, generally providing much tighter bounds
      for the computed quantities. The resulting octrees are accordingly
      much smaller, and the rendering faster.  We also describe
      applications of affine arithmetic to intersection and ray tracing
      of implicit surfaces.
  }
}