Publications by Tizian Lucien Zeltner

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

Nicolas Julien Roussel, Merlin Eléazar Nimier-David, Wenzel Alban Jakob, Tizian Lucien Zeltner

We present a fast and simple technique to convert images into a radiance surface-based scene representation. Building on existing radiance volume reconstruction algorithms, we introduce a subtle yet impactful modification of the loss function requiring cha ...

ACM2025

Practical Multiple-Scattering Sheen Using Linearly Transformed Cosines

Tizian Lucien Zeltner

We introduce a new volumetric sheen BRDF that approximates scattering observed in surfaces covered with normally-oriented fibers. Our previous sheen model was motivated by measured cloth reflectance, but lacked significant backward scattering. The model pr ...

ASSOC COMPUTING MACHINERY2022

Light Path Gradients for Forward and Inverse Rendering

Tizian Lucien Zeltner

Physically based rendering is a process for photorealistic digital image synthesis and one of the core problems in computer graphics. It involves simulating the light transport, i.e. the emission, propagation, and scattering of light through a virtual scen ...

EPFL2021

Monte Carlo Estimators for Differential Light Transport

Sébastien Nicolas Speierer, Wenzel Alban Jakob, Tizian Lucien Zeltner

Physically based differentiable rendering algorithms propagate derivatives through realistic light transport simulations and have applications in diverse areas including inverse reconstruction and machine learning. Recent progress has led to unbiased metho ...

ASSOC COMPUTING MACHINERY2021

Image-Based Acquisition and Modeling of Polarimetric Reflectance

Xin Tong, Wenzel Alban Jakob, Tizian Lucien Zeltner

Realistic modeling of the bidirectional reflectance distribution function (BRDF) of scene objects is a vital prerequisite for any type of physically based rendering. In the last decades, the availability of databases containing real-world material measurem ...

ASSOC COMPUTING MACHINERY2020

Slope-Space Integrals for Specular Next Event Estimation

Wenzel Alban Jakob, Tizian Lucien Zeltner, Guillaume Rémi Bruno Loubet

Monte Carlo light transport simulations often lack robustness in scenes containing specular or near-specular materials. Widely used uni- and bidirectional sampling strategies tend to find light paths involving such materials with insufficient probability, ...

ASSOC COMPUTING MACHINERY2020

Specular Manifold Sampling for Rendering High-Frequency Caustics and Glints

Wenzel Alban Jakob, Tizian Lucien Zeltner

Scattering from specular surfaces produces complex optical effects that are frequently encountered in realistic scenes: intricate caustics due to focused reflection, multiple refraction, and high-frequency glints from specular microstructure. Yet, despite ...

ASSOC COMPUTING MACHINERY2020

Mitsuba 2: A Retargetable Forward and Inverse Renderer

Merlin Eléazar Nimier-David, Wenzel Alban Jakob, Tizian Lucien Zeltner, Delio Aleardo Vicini

Modern rendering systems are confronted with a dauntingly large and growing set of requirements: in their pursuit of realism, physically based techniques must increasingly account for intricate properties of light, such as its spectral composition or polar ...

ASSOC COMPUTING MACHINERY2019

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

Wenzel Alban Jakob, Tizian Lucien Zeltner

We present a versatile computational framework for modeling the reflective and transmissive properties of arbitrarily layered anisotropic material structures. Given a set of input layers, our model synthesizes an effective BSDF of the entire structure, whi ...

ASSOC COMPUTING MACHINERY2018