Steve Trettel
Hello! I'm a mathematician and artist at the University of San Francisco, who works in geometry and mathematical visualization. This site collects my illustration, code, and writing. Sometimes I also take photographs and cook.
Art
Graphics
Showing 8 of 290 graphics Browse all →Demos
Showing 8 of 372 demos Browse all →Software
pathtracer
Photorealistic rendering of signed distance fields via unidirectional path tracing in GLSL.
shader-sandbox
An npm package for running Shadertoy-like shaders and beyond easily on your local machine.
threejs-demos
A system for creating and running Three.js animations.
Blog
- Gauss' Linking Number IV Feb 2026
- Gauss' Linking Number III Feb 2026
- Gauss' Linking Number II Feb 2026
- Gauss' Linking Number I Feb 2026
- Limit Schottky Groups Nov 2025
Books & Course Notes
Modern Geometry
Notes / textbook for a 1 semester undergraduate course in geometry, taking calculus as the foundations. Covers Euclidean, Spherical and a bit of Hyperbolic geometry.
Multivariable Calculus
Supplementary Course Notes for the multivariable calculus course I teach at USF, with live animations.
Reaching for Infinity
A year-long advanced undergraduate real analysis textbook, with an emphasis on historically important problems.
Shaders
Course notes for GPU shader programming as a tool for mathematical visualization, covering fractals, implicit surfaces, tilings, and physical simulations in GLSL.
Websites
Algebraic Starscapes
Geodesic Boards
Raymarching Thurston Geometries
Visualizing Elliptic Curves over Finite Fields
This semester I am on sabbatical in Europe, and not teaching. (previous semesters)
- Fall 2026 Calculus I (MATH 109)
- Fall 2026 Differential Equations (MATH 340)
- Fall 2025 Linear Algebra (MATH 230)
- Fall 2025 Multivariable Calculus (MATH 211)
- Spring 2025 Multivariable Calculus (MATH 211)
- Spring 2025 Real Analysis (MATH 453)
- Fall 2024 Linear Algebra (MATH 229) — 2 sections
- Fall 2024 Multivariable Calculus (MATH 211)
- Spring 2024 Calculus I (MATH 109)
- Spring 2024 Real Analysis (MATH 453)
- Fall 2023 Multivariable Calculus (MATH 211)
- Fall 2023 Foundations of Geometry (MATH 380)
- Spring 2023 Real Analysis (MATH 453)
- Spring 2023 Multivariable Calculus (MATH 211)
- Fall 2022 Calculus I (MATH 109)
- Fall 2022 Calculus II (MATH 110)
When not at USF, I'm occasionally on the road for math — upcoming trips below, and where I've recently been. I particularly enjoy giving undergraduate colloquia and public lectures — if you'd like to have me visit, please get in touch.
- Jan 18 – Apr 3 Institut Henri Poincaré Illustration as a Mathematical Research Technique (semester program) Paris, France
- Apr 4 – Jun 18 Max Planck Institute for Mathematics in the Sciences Visiting Researcher Leipzig, Germany
- Jun 21–26 BIRS — Casa Matemática Oaxaca Frontiers in Surface Topology: Compact, Non-Compact, and Beyond Oaxaca, Mexico
- Jul 21–31 International Congress of Mathematicians Invited Mathematical Art Exhibition Philadelphia, PA
- Aug 5–8 MAA MathFest Invited Address Boston, MA
- Aug 11–15 ICERM — Illustrating Mathematics Speaker Providence, RI
- Jul 14–18 Bridges Math Art Conference Speaker Eindhoven, Netherlands
- May 25 – Jun 12 Max Planck Institute for Mathematics in the Sciences Visiting Researcher Leipzig, Germany
Recent Papers
- Classical Optics for Charged Black Holes Bridges Math Art 2025 Conference Proceedings, 2025
- Elliptic Curves and the Hopf Fibration Bridges Math Art Conference Proceedings, 2025, 2025
- Degenerations of the product geometries in projective space that contain Nil Topology and its Applications, 2024
- Visualizing Knot Complements MAA Focus, 2023
- Modeling Graphs Beyond Hyperbolic: Graph Neural Networks in Symmetric Positive Definite Matrices European Congress of Machine Learning, 2023
Recent Talks
- Visualizing Elliptic Curves over Finite Fields Institut Henri Poincare, 2026
- A Gravitational Photograph ICERM — Brown University, 2025
- Charged Black Holes TU Eindhoven, 2025
- 4d Knot Penn State — Student Colloquium, 2025
- Geometry of Graph Embeddings Penn State — Research Seminar, 2025