Artists

Stephen J Trettel

Assistant Professor of Mathematics

University of San Francisco

San Francisco California, USA

strettel@usfca.edu

https://www.stevejtrettel.site

Statement

When illustrating mathematics, I focus on illustrating low-dimensional geometric objects which embody both visual and mathematical beauty. My primary medium consists of 3-dimensional computer graphics, and I typically write a new program for each piece. I aim to capture each mathematical object in its natural environment, and provide a view of what it 'would really look like' were it possible to visit the abstract world that it calls home.

Artworks

Image for entry 'Limit set in Jade'

Limit set in Jade

51.0 x 61.0 cm

Output of a custom program written in GLSL (graphics language on GPU)

2023

Discrete groups of symmetries of hyperbolic space leave a trace of their geometry out at infinity - as an intricate collection of points known as the *limit set*. This piece depicts one such limit set - a fractal living in the 3-sphere arising from a group of symmetries of hyperbolic 4-space. To compute the image, a program was written to raytrace points of the fractal using the escape-time algorithm of Jos Leys, stereographically projected into $\mathbb{R}^3$. Then to render, a custom path-tracer was written to simulate a "jade-like" material: each pixel is colored by simulating 50,000 individual photons, each of which scatters inside of the material on a variant of a random walk.