Opal is a mineraloid which has a distinctive optical effect: ‘play of color,’ and it has been utilized
for a gemstone because it displays beautiful and complex iridescent patterns in itself. Visual simulation of
play of color is in demand from a viewpoint of designing the texture of gemstones.

Results of visuual simulation of opal using three-dimensional Voronoi tessellation

In this study, we propose a new method for modeling the internal structure of opal using three-dimensional Voronoi tessellation, which attempts to display patterns based on crystallography.

Control of internal colors by specifying the particle size of silica spheres

Classification of this study

This study is far from phenomenological modeling because it does not use a method to infer the internal structure from the pattern of `play of color.’
Although approximating the internal structure of opal using Voronoi diagrams reduces the amount of time and space required for calculations, the model is based on crystallography, so it can be said to have a stronger physical aspect than an artificial aspect.


Name Affiliation Web site
Soma Yokota Keio University
Shumpei Sugita Keio University





Domestic presentations
  1. Soma Yokota, Shumpei Sugita, Issei Fujishiro: “Visual Simulation of ‘Play of color’ Ovserved in Opal Using Voronoi-tessellation Model,” in Proceedings of SIG Technical Reports, Vol. 2022–CG–185, No. 3, pp. 1-6, March 11-12,2022 (in Japanese).
  2. Soma Yokota, Issei Fujishiro: “Voronoi Tessellation-based Opal Modeling for Visual Simulation of Play of Color,” in Proceedings of the 84th National Convention of Information Proceedings Society of Japan, Vol. 4, pp. 355-356 (7ZG–02), Ehime University Johoku Campas, Ehime, March 3-5, 2022, Vol. 4, pp. 355-356 (7ZG–02), Student Encouragement Award (in Japanese).


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