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Item Selective Caching in Procedural Texture Graphs for Path Tracing(The Eurographics Association, 2025) Schüßler, Vincent; Hanika, Johannes; Sauvage, Basile; Dischler, Jean-Michel; Dachsbacher, Carsten; Wang, Beibei; Wilkie, AlexanderProcedural texturing is crucial for adding details in large-scale rendering. Typically, procedural textures are represented as computational graphs that artists can edit. However, as scene and graph complexity grow, evaluating these graphs becomes increasingly expensive for the rendering system. Performance is greatly affected by the evaluation strategy: Precomputing textures into high resolution maps is straightforward but can be inefficient, while shade-on-hit architectures and tile-based caches improve efficiency by evaluating only necessary data. However, the ideal choice of strategy depends on the application context. We present a new method to dynamically select which texture graph nodes to cache within a rendering system that supports filtered texture graph evaluation and tile-based caching. Our method allows us to construct an optimized evaluation strategy for each scene. Cache-friendly nodes are identified using data-driven predictions based on statistics of requested texture footprints, gathered during a profiling phase. We develop a statistical model that fits profiling data and predicts how caching specific nodes affects evaluation efficiency and storage demands. Our approach can be directly integrated into a rendering system or used to analyze renderer data, helping practitioners to optimize performance in their workflows.Item Efficient Modeling and Rendering of Iridescence from Cholesteric Liquid Crystals(The Eurographics Association, 2025) Fourneau, Gary; Barla, Pascal; Pacanowski, Romain; Wang, Beibei; Wilkie, AlexanderWe introduce a novel approach to the efficient modeling and rendering of Cholesteric Liquid Crystals (CLCs), materials known for producing colorful effects due to their helical molecular structure. CLCs reflect circularly-polarized light within specific spectral bands, making their accurate simulation challenging for realistic rendering in Computer Graphics. Using the two-wave approximation from the Photonics literature, we develop a piecewise spectral reflectance model that improves the understanding of how light interact with CLCs for arbitrary incident angles. Our reflectance model allows for more efficient spectral rendering and fast integration into RGB-based rendering engines. We show that our approach is able to reproduce the unique visual properties of both natural and man-made CLCs, while keeping the computation fast enough for interactive applications and avoiding potential spectral aliasing issues.Item Radiative Backpropagation with Non-Static Geometry(The Eurographics Association, 2025) Worchel, Markus; Finnendahl, Ugo; Alexa, Marc; Wang, Beibei; Wilkie, AlexanderRadiative backpropagation-based (RB) methods efficiently compute reverse-mode derivatives in physically-based differentiable rendering by simulating the propagation of differential radiance. A key assumption is that differential radiance is transported like normal radiance. We observe that this holds only when scene geometry is static and demonstrate that current implementations of radiative backpropagation produce biased gradients when scene parameters change geometry. In this work, we derive the differential transport equation without assuming static geometry. An immediate consequence is that the parameterization matters when the sampling process is not differentiated: only surface integrals allow a local formulation of the derivatives, i.e., one in which moving surfaces do not affect the entire path geometry. While considerable effort has been devoted to handling discontinuities resulting from moving geometry, we show that a biased interior derivative compromises even the simplest inverse rendering tasks, regardless of discontinuities. An implementation based on our derivation leads to systematic convergence to the reference solution in the same setting and provides unbiased RB interior derivatives for path-space differentiable rendering.Item Procedural Bump-based Defect Synthesis for Industrial Inspection(The Eurographics Association, 2025) Mao, Runzhou; Garth, Christoph; Gospodnetic, Petra; Wang, Beibei; Wilkie, AlexanderAutomated defect detection is critical for quality control, but collecting and annotating real-world defect images remains costly and time-consuming, motivating the use of synthetic data. Existing methods such as geometry-based modeling, normal maps, and image-based approaches often struggle to balance realism, efficiency, and scalability. We propose a procedural method for synthesizing small-scale surface defects using gradient-based bump mapping and triplanar projection. By perturbing surface normals at shading time, our approach enables parameterized control over diverse scratch and dent patterns, while avoiding mesh edits, UV mapping, or texture lookup. It also produces pixel-accurate defect masks for annotation. Experimental results show that our method achieves comparable visual quality to geometry-based modeling, with lower computational overhead and improved surface continuity over static normal maps. The method offers a lightweight and scalable solution for generating high-quality training data for industrial inspection tasks.Item From Optical Measurement to Visual Comfort Analysis: a Complete Simulation Workflow with Ocean™'s Glare Map Post-processing(The Eurographics Association, 2025) Bandeliuk, Oleksandra; Besse, Grégoire; Pierrard, Thomas; Berthier, Estelle; Wang, Beibei; Wilkie, AlexanderLighting critically influences public safety and visual comfort across environments. Discomfort glare, in particular, poses a major challenge. We here introduce Ocean™'s glare map, a fast, high-fidelity glare evaluation tool that computes key indices (UGR, DGP, GR) through post-processing of spectral global illumination simulations. Beyond whole-scene assessments, our glare map tool uniquely offers per-source glare ratings, enabling precise design optimization. Through three practical use cases, we demonstrate the effectiveness of our tool for operational design and show how changes in illumination and material properties directly affect glare, supporting safer and more efficient lighting designs.Item Joint Gaussian Deformation in Triangle-Deformed Space for High-Fidelity Head Avatars(The Eurographics Association, 2025) Lu, Jiawei; Guang, Kunxin; Hao, Conghui; Sun, Kai; Yang, Jian; Xie, Jin; Wang, Beibei; Wang, Beibei; Wilkie, AlexanderCreating 3D human heads with mesoscale details and high-fidelity animation from monocular or sparse multi-view videos is challenging. While 3D Gaussian splatting (3DGS) has brought significant benefits into this task, due to its powerful representation ability and rendering speed, existing works still face several issues, including inaccurate and blurry deformation, and lack of detailed appearance, due to difficulties in complex deformation representation and unreasonable Gaussian placement. In this paper, we propose a joint Gaussian deformation method by decoupling the complex deformation into two simpler deformations, incorporating a learnable displacement map-guided Gaussian-triangle binding and a neural-based deformation refinement, improving the fidelity of animation and details of reconstructed head avatars. However, renderings of reconstructed head avatars at unseen views still show artifacts, due to overfitting on sparse input views. To address this issue, we leverage synthesized pseudo views rendered with fitted textured 3DMMs as priors to initialize Gaussians, which helps maintain a consistent and realistic appearance across various views. As a result, our method outperforms existing state-of-the-art approaches with about 4.3 dB PSNR in novel-view synthesis and about 0.9 dB PSNR in self-reenactment on multi-view video datasets. Our method also preserves high-frequency details, exhibits more accurate deformations, and significantly reduces artifacts in unseen views.Item Adaptive Multiple Control Variates for Many-Light Rendering(The Eurographics Association, 2025) Xu, Xiaofeng; Wang, Lu; Wang, Beibei; Wilkie, AlexanderMonte Carlo integration estimates the path integral in light transport by randomly sampling light paths and averaging their contributions. However, in scenes with many lights, the resulting estimates suffer from noise and slow convergence due to highfrequency discontinuities introduced by complex light visibility, scattering functions, and emissive properties. To mitigate these challenges, control variates have been employed to approximate the integrand and reduce variance. While previous approaches have shown promise in direct illumination application, they struggle to efficiently handle the discontinuities inherent in manylight environments, especially when relying on a single control variate. In this work, we introduce an adaptive method that generates multiple control variates tailored to the spatial distribution and number of lights in the scene. Drawing inspiration from hierarchical light clustering methods like Lightcuts, our approach dynamically determines the number of control variates. We validate our method on the direct illumination problem in scenes with many lights, demonstrating that our adaptive multiple control variates not only outperform single control variate strategy but also achieve a modest improvement over current stateof- the-art many-light sampling techniques.Item Less can be more: A Footprint-driven Heuristic to skip Wasted Connections and Merges in Bidirectional Rendering(The Eurographics Association, 2025) Yazici, Ömercan; Grittmann, Pascal; Slusallek, Philipp; Wang, Beibei; Wilkie, AlexanderBidirectional rendering algorithms can robustly render a wide range of scenes and light transport effects. Their robustness stems from the fact that they combine a huge number of sampling techniques: Paths traced from the camera are combined with paths traced from the lights by connecting or merging their vertices in all possible combinations. The flip side of this robustness is that efficiency suffers because most of these connections and merges are not useful - their samples will have a weight close to zero. Skipping these wasted computations is hence desirable. Prior work has attempted this via manual parameter tuning, by classifying materials as ''specular'', ''glossy'', or ''diffuse'', or via costly data-driven adaptation. We, instead, propose a simple footprint-driven heuristic to selectively enable only the most impactful bidirectional techniques. Our heuristic is based only on readily available PDF values, does not require manual tuning, supports arbitrarily complex material systems, and does not require precomputation.Item Bidirectional Plateau-Border Scattering Distribution Function for Realistic and Efficient Foam Rendering(The Eurographics Association, 2025) Li, Ruizeng; Liu, Xinyang; Wang, Runze; Shen, Pengfei; Liu, Ligang; Wang, Beibei; Wang, Beibei; Wilkie, AlexanderLiquid foams are a common phenomenon in our daily life. In computer graphics, rendering realistic foams remains challenging due to their complex geometry and light interactions within the foam. While the structure of the liquid foams has been well studied in the field of physics, it's rarely leveraged for rendering, even though it is essential for achieving realistic appearances. In physics, the intersection of two bubbles creates a liquid-carrying channel known as the Plateau border (PB). In this paper, we introduce the Plateau border into liquid foam rendering by explicitly modeling it at the geometric level. Although modeling of PBs enhances visual realism with path tracing, it suffers from extensive rendering costs due to multiple scattering effects within the medium contained in the PB. To tackle this, we propose a novel scattering function that models the aggregation of scattering within the medium surrounded by a Plateau border, termed the bidirectional Plateau-border scattering distribution function (BPSDF). Since no analytical formulation can be derived for the BPSDF, we propose a neural representation, together with importance sampling and probability distribution functions, to enable Monte Carlo-based rendering. By integrating our BPSDF into path tracing, our method achieves both realistic and efficient rendering of liquid foams, producing images with high fidelity.