Crater illusion and Hollow-mask illusion are famous examples of depth reversal. Crater illusion shows that depth perception of the craters changes due to the shading effect. Hollow-mask illusion shows the similar depth reversal phenomenon and moreover the mask appears to follow the moving viewer. “Deluding arrows” (A. Tomoeda, K. Sugihara, 2012) is a new illusionary solid with hollow structure, which is obtained from some geometric calculations. Furthermore, “Deluding arrows with shading” (A. Tomoeda, J. Ono, K. Sugihara, 2013) succeeds in making the planar design appear to solid structure by considering shading effect of each surface. This paper presents design procedures for these hollow-mask type illusionary solid built on the computation of geometric shape for a give polygon and shading effect of each surface.

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