Modular bivariate quadratic functions (quadratic functions of two variables over the integers modulo q) can be used to procedurally generate gray-scale and color textures that resemble ornamentation, skin, scales, feathers, textiles, and optical illusions. The latter appear to include distorted perspective, false 3D, and Fechner colors, the combination of which is disturbing to some viewers. This technique is particularly suited to parallel execution using a pixel shader since each pixel is computed independently by performing a small number of arithmetic operations on the pixel coordinates. A prototype browser-based procedural texture generator with an interface suitable for use by non-mathematicians such as designers and artists is described.

Brief Bio:

Ian Parberry is a pioneer of academic game development education and
research who has been teaching game programming to undergraduates
since 1993, when he established the Laboratory for Recreational
Computing (LARC). LARC alumni have credits on at least 66 commercial
video games that have sold a total of over 180 million copies,
estimated to be worth more than \$9 billion in revenue. The most famous
of these alumni is Jason West, co-founder of the Call of Duty
franchise. Ian was named an ACM Distinguished Scientist in 2015.