About me

I'm a Senior Research Scientist at NVIDIA interested in appearance modeling, light transport algorithms, and differentiable physically based rendering.

I obtained my PhD from EPFL's Realistic Graphics Lab, where I was advised by Wenzel Jakob. During my time there, I spent a summer at Walt Disney Animation Studios where I contributed to the Hyperion Renderer. Before that, I completed my Master's degree at ETH Zurich with a focus on visual computing.

Publications

  • Radiance Surfaces: Optimizing Surface Representations with a 5D Radiance Field Loss

    Ziyi Zhang, Nicolas Roussel, Thomas Müller, Tizian Zeltner, Merlin Nimier-David, Fabrice Rousselle, and Wenzel Jakob
    SIGGRAPH 2025 (Conference Track)
    Project Page Paper GitHub

  • Generative Detail Enhancement for Physically Based Materials

    Saeed Hadadan, Benedikt Bitterli, Tizian Zeltner, Jan Novák, Fabrice Rousselle, Jacob Munkberg, Jon Hasselgren, Bartlomiej Wronski, and Matthias Zwicker
    SIGGRAPH 2025 (Conference Track)
    Project Page Paper

  • Real-Time Neural Appearance Models

    Tizian Zeltner *, Fabrice Rousselle *, Andrea Weidlich *, Petrik Clarberg *, Jan Novák *, Benedikt Bitterli *, Alex Evans, Tomáš Davidovič, Simon Kallweit, and Aaron Lefohn

    * Equal contribution. Order determined by a rock-paper-scissors tournament.

    In Transactions on Graphics (Presented at SIGGRAPH 2024)
    Project Page Paper

  • Microfacet Theory for Non-Uniform Heightfields

    Eugene d'Eon, Benedikt Bitterli, Andrea Weidlich, and Tizian Zeltner
    SIGGRAPH 2023 (Conference Track)
    Project Page Paper

  • Practical Multiple-Scattering Sheen Using Linearly Transformed Cosines

    Tizian Zeltner, Brent Burley, and Matt Jen-Yuan Chiang
    SIGGRAPH 2022 Talk
    Project Page Abstract GitHub

  • Monte Carlo Estimators for Differential Light Transport

    Tizian Zeltner, Sébastien Speierer, Iliyan Georgiev, and Wenzel Jakob
    In Transactions on Graphics (Proceedings of SIGGRAPH 2021)
    Project Page Paper GitHub

  • Slope-Space Integrals for Specular Next Event Estimation

    Guillaume Loubet, Tizian Zeltner, Nicolas Holzschuch, and Wenzel Jakob
    In Transactions on Graphics (Proceedings of SIGGRAPH Asia 2020)
    Project Page Paper

  • Specular Manifold Sampling for Rendering High-Frequency Caustics and Glints

    Tizian Zeltner, Iliyan Georgiev, and Wenzel Jakob
    In Transactions on Graphics (Proceedings of SIGGRAPH 2020)
    Project Page Paper GitHub

  • Image-Based Acquisition and Modeling of Polarimetric Reflectance

    Seung-Hwan Baek, Tizian Zeltner, Hyun Jin Ku, Inseung Hwang, Xin Tong, Wenzel Jakob, and Min H. Kim
    In Transactions on Graphics (Proceedings of SIGGRAPH 2020)
    Project Page Paper

  • Mitsuba 2: A Retargetable Forward and Inverse Renderer

    Merlin Nimier-David *, Delio Vicini *, Tizian Zeltner, and Wenzel Jakob

    * Joint first authors.

    In Transactions on Graphics (Proceedings of SIGGRAPH Asia 2019)
    Project Page Paper GitHub

  • The Layer Laboratory: A Calculus for Additive and Subtractive Composition of Anisotropic Surface Reflectance

    Tizian Zeltner and Wenzel Jakob
    In Transactions on Graphics (Proceedings of SIGGRAPH 2018)
    Project Page Paper GitHub

PhD Thesis

  • Light Path Gradients for Forward and Inverse Rendering

    Tizian Zeltner, advised by Wenzel Jakob
    École Polytechnique Fédérale de Lausanne, Dec. 2021
    Project Page Thesis

Side Projects

  • An Overview of Polarized Rendering

    A detailed document summarizing the mathematical framework used for polarized light transport and its implementation in the Mitsuba 3 renderer.
    Project Page

  • 2D Specular Manifold Visualizer

    A 2D implementation of some light transport algorithms using the specular manifold constraint framework. This can either be used to prototype new ideas or generate animated visualizations.
    GitHub

  • tonemapper

    A small application to compare and apply various global tone mapping operators to high-dynamic-range images. It features an interactive preview and a simple GUI to tweak different parameters.
    GitHub

  • Noodles: A Path Tracer Made of Blender Nodes

    A small path tracer built fully inside Blender's shader node editor. Based on a silly joke idea that got way out of hand.
    Project Page

  • Music Box for Playdate

    A tiny musical instrument for the Playdate console. Select one of the well-known tunes included in the app and start turning the crank to advance the music. You can also get creative and compose your own short song with the built-in editor.
    Itch.io

  • The Music of Middle-earth

    An unofficial companion app to index Howard Shore's music for the 'Lord of the Rings' films.
    The film score consists of more than 80 leitmotifs or themes that relate to specific characters, locations or cultures of Middle-earth. This project tries to provide an interactive listening experience that highlights all theme occurrences throughout the soundtrack in form of a simple, user-friendly application.
    Project Page

Study Projects

  • Light Stippling and Halftoning

    Master Thesis at ETH Zurich, August 2016
    A method for the design of perforated surfaces that project grayscale shadow images onto nearby walls when illuminated by a light source.
    Project Page

  • Image Synthesis

    Course Project at ETH Zurich, Spring Semester 2015
    Implementation of various features in a physically-based renderer. The image created for the final project won 1st place at the ETH Rendering Competition 2015.
    Built using the Nori framework.
    Project Page Image Course Website

  • Physically-based Simulation

    Course Project at ETH Zurich, Fall Semester 2014
    A real-time Spinning Top Simulation built for the yearly competition held in this course, in collaboration with Milan Bombsch. The main challenges were to implement rigid-body dynamics and collision detection between complex geometry.
    GitHub YouTube Course Website

  • An AR Framework for City-Wide Treasure Hunting

    Bachelor Thesis at ETH Zurich, September 2014
    A framework to design and build city-wide Augmented Reality scavenger hunt games together with an implementation of an example game for mobile devices.
    Project Page GitHub