摘要：＂Hollow mask illusion＂ is an optical illusion and appears due to an error in the process of reconstructing the three-dimensional objects from our two-dimensional retinal image. In this paper, we present a computational method to create ＂Hollow mask＂ type new illusionary solid by calculating the hollow structure and its shading. The straight line Voronoi diagram for a given shape obtains the three-dimensional vertices of the hollow structure and the shading effect on each surface is calculated under the assumption that each surface has diffusely reflecting surface（Lambertian reflectance）. We also show two examples of our new illusionary solid works.