Shell mapping is the method that represents the fine structure of surfaces by mapping three-dimensional texture space one-to-one onto triangular prisms obtained by extruding existing triangular polygons in the direction of their normals. In comparison to displacement mapping, shell mapping enables more complex representations because it can define three-dimensional geometric shapes as fine structures in addition to concavities and convexities.

In this study, the texture space is represented by volume data in order to perform shell mapping with a high degree of freedom for translucent materials and implicit function surfaces. One possible implementation method is to divide the prism into tetrahedra and map the texture space linearly at each segment, but this method results in artefacts at the boundaries of the tetrahedra. To address this issue, linear rays are mapped to the texture space, and non-linear ray tracing is calculated within the texture space. Additionally, hierarchical volume data is utilized to achieve efficient volume rendering.

When a ray intersects prisms, volume rendering is calculated in that section


Name Affiliation Web site
Mayuka Kuwana Keio University



  1. Mayuka Kuwana, Issei Fujishiro:”Volumetric Shell Mapping Using Nonlinear Rays, ” in Proceedings of SIG Technical Reports, Vol. 2024–CG–193, No. 10, pp. 1-6, Keio University, March 18-19, 2024, Student presentation award (in Japanese).
  2. Mayuka Kuwana, Issei Fujishiro:”Volumetric shell mapping using nonlinear ray tracing, ” in Proceedings of the 86th National Convention of Information Proceedings Society of Japan, Vol. 2, pp. 169-170 (1P–05), Kanagawa University, March 15, 2024, Student encouragement award (in Japanese).


  1. Mayuka Kuwana:”Volumetric shell mapping using nonlinear rays”, Second Vision, graphics and sensing workshop, poster, The University of Chiba, April 19, 2024


  1. Grant-in-Aid for Scientific Research(A):21H04916

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