author = "Miranda, F{\'a}bio Markus and Celes, Waldemar",
          affiliation = "{Tecgraf/PUC-Rio - Computer Science Department} and 
                         {Tecgraf/PUC-Rio - Computer Science Department}",
                title = "Accurate volume rendering of unstructured hexahedral meshes",
            booktitle = "Proceedings...",
                 year = "2011",
               editor = "Lewiner, Thomas and Torres, Ricardo",
         organization = "Conference on Graphics, Patterns and Images, 24. (SIBGRAPI)",
            publisher = "IEEE Computer Society",
              address = "Los Alamitos",
             keywords = "rendering, hexahedral mesh, unstructured mesh, ray integral.",
             abstract = "Important engineering applications use unstructured hexahedral 
                         meshes for numerical simulations. Hexahedral cells, when compared 
                         to tetrahedral ones, tend to be more numerically stable and to 
                         require less mesh refinement. However, volume visualization of 
                         unstructured hexahedral meshes is challenging due to the trilinear 
                         variation of scalar fields inside the cells. The conventional 
                         solution consists in subdividing each hexahedral cell into five or 
                         six tetrahedra, approximating a trilinear variation by a piecewise 
                         linear function. This results in inaccurate images and increases 
                         the memory consumption. In this paper, we present an accurate 
                         ray-casting volume rendering algorithm for unstructured hexahedral 
                         meshes. In order to capture the trilinear variation along the ray, 
                         we propose the use of quadrature integration. A set of 
                         computational experiments demonstrates that our proposal produces 
                         accurate results, with reduced memory footprint. The entire 
                         algorithm is implemented on graphics cards, ensuring competitive 
  conference-location = "Macei{\'o}",
      conference-year = "Aug. 28 - 31, 2011",
             language = "en",
           targetfile = "paper.pdf",
        urlaccessdate = "2020, Sep. 19"