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Item Transparent and Specular Object Reconstruction(The Eurographics Association, 2008) Ihrke, Ivo; Kutulakos, Kiriakos N.; Lensch, Hendrik P. A.; Magnor, Marcus; Heidrich, Wolfgang; Theoharis Theoharis and Philip DutreThis state of the art report covers reconstruction methods for transparent and specular objects or phenomena. While the 3D acquisition of opaque surfaces with lambertian reflectance is a well-studied problem, transparent, refractive, specular and potentially dynamic scenes pose challenging problems for acquisition systems. This report reviews and categorizes the literature in this field. Despite tremendous interest in object digitization, the acquisition of digital models of transparent or specular objects is far from being a solved problem. On the other hand, real-world data is in high demand for applications such as object modeling, preservation of historic artifacts and as input to data driven modeling techniques. With this report we aim at providing a reference for and an introduction to the field of transparent and specular object reconstruction. We describe acquisition approaches for different classes of objects. Transparent objects/phenomena that do not change the straight ray geometry can be found foremost in natural phenomena. Refraction effects are usually small and can be considered negligible for these objects. Phenomena as diverse as fire, smoke, and interstellar nebulae can be modeled using a straight ray model of image formation. Refractive and specular surfaces on the other hand change the straight rays into usually piecewise linear ray paths, adding additional complexity to the reconstruction problem. Translucent objects exhibit significant sub-surface scattering effects rendering traditional acquisition approaches unstable. Different classes of techniques have been developed to deal with these problems and good reconstruction results can be achieved with current state-of-the-art techniques. However, the approaches are still specialized and targeted at very specific object classes. We classify the existing literature and hope to provide an entry point to this exiting field.Item Perception-driven Accelerated Rendering(The Eurographics Association and John Wiley & Sons Ltd., 2017) Weier, Martin; Stengel, Michael; Roth, Thorsten; Didyk, Piotr; Eisemann, Elmar; Eisemann, Martin; Grogorick, Steve; Hinkenjann, André; Kruijff, Ernst; Magnor, Marcus; Myszkowski, Karol; Slusallek, Philipp; Victor Ostromoukov and Matthias ZwickerAdvances in computer graphics enable us to create digital images of astonishing complexity and realism. However, processing resources are still a limiting factor. Hence, many costly but desirable aspects of realism are often not accounted for, including global illumination, accurate depth of field and motion blur, spectral effects, etc. especially in real-time rendering. At the same time, there is a strong trend towards more pixels per display due to larger displays, higher pixel densities or larger fields of view. Further observable trends in current display technology include more bits per pixel (high dynamic range, wider color gamut/fidelity), increasing refresh rates (better motion depiction), and an increasing number of displayed views per pixel (stereo, multi-view, all the way to holographic or lightfield displays). These developments cause significant unsolved technical challenges due to aspects such as limited compute power and bandwidth. Fortunately, the human visual system has certain limitations, which mean that providing the highest possible visual quality is not always necessary. In this report, we present the key research and models that exploit the limitations of perception to tackle visual quality and workload alike. Moreover, we present the open problems and promising future research targeting the question of how we can minimize the effort to compute and display only the necessary pixels while still offering a user full visual experience.Item A Nonobscuring Eye Tracking Solution for Wide Field-of-View Head-mounted Displays(The Eurographics Association, 2014) Stengel, Michael; Grogorick, Steve; Rogge, Lorenz; Magnor, Marcus; Mathias Paulin and Carsten DachsbacherWe present a solution for integrating a binocular eye tracker into current state-of-the-art lens-based head-mounted displays (HMDs) without affecting the available field-of-view on the display. Estimating the relative eye gaze of the user opens the door for HMDs to a much wider spectrum of virtual reality applications and games. Further, we present a concept of a low-cost head-mounted display with eye tracking and discuss applications which strongly depend on or benefit from gaze estimation.Item General and Robust Error Estimation and Reconstruction for Monte Carlo Rendering(The Eurographics Association and John Wiley & Sons Ltd., 2015) Bauszat, Pablo; Eisemann, Martin; Eisemann, Elmar; Magnor, Marcus; Olga Sorkine-Hornung and Michael WimmerAdaptive filtering techniques have proven successful in handling non-uniform noise in Monte-Carlo rendering approaches. A recent trend is to choose an optimal filter per pixel from a selection of non spatially-varying filters. Nonetheless, the best filter choice is difficult to predict in the absence of a reference rendering. Our approach relies on the observation that the reconstruction error is locally smooth for a given filter. Hence, we propose to construct a dense error prediction from a small set of sparse but robust estimates. The filter selection is then formulated as a non-local optimization problem, which we solve via graph cuts, to avoid visual artifacts due to inconsistent filter choices. Our approach does not impose any restrictions on the used filters, outperforms previous state-of-the-art techniques and provides an extensible framework for future reconstruction techniques.Item Capture and Statistical Modeling of Arm-Muscle Deformations(The Eurographics Association and Blackwell Publishing Ltd., 2013) Neumann, Thomas; Varanasi, Kiran; Hasler, Nils; Wacker, Markus; Magnor, Marcus; Theobalt, Christian; I. Navazo, P. PoulinWe present a comprehensive data-driven statistical model for skin and muscle deformation of the human shoulderarm complex. Skin deformations arise from complex bio-physical effects such as non-linear elasticity of muscles, fat, and connective tissue; and vary with physiological constitution of the subjects and external forces applied during motion. Thus, they are hard to model by direct physical simulation. Our alternative approach is based on learning deformations from multiple subjects performing different exercises under varying external forces. We capture the training data through a novel multi-camera approach that is able to reconstruct fine-scale muscle detail in motion. The resulting reconstructions from several people are aligned into one common shape parametrization, and learned using a semi-parametric non-linear method. Our learned data-driven model is fast, compact and controllable with a small set of intuitive parameters - pose, body shape and external forces, through which a novice artist can interactively produce complex muscle deformations. Our method is able to capture and synthesize fine-scale muscle bulge effects to a greater level of realism than achieved previously. We provide quantitative and qualitative validation of our method.Item The Split Grid - A Hierarchical 1D-Grid-based Acceleration Data Structure for Ray Tracing(The Eurographics Association, 2014) Bauszat, Pablo; Kastner, Marc Aurel; Eisemann, Martin; Magnor, Marcus; Mathias Paulin and Carsten DachsbacherWe present a new acceleration structure for ray tracing called the Split Grid. Combining concepts of hierarchical grids, kd-trees and Bounding Volume Hierarchies (BVHs), our approach is based on the idea of nesting 1D-grids. Our proposed acceleration structure is compact in storage, adaptive to the scene geometry and can be traversed using a fast and efficient traversal scheme. We show that the Split Grid is comparable to other current state-of-theart acceleration structures regarding traversal performance and memory footprint. While other data structures usually achieve these levels of performance only due to a complex and expensive construction process (e.g. using the Surface Area Heuristic (SAH) [MB90]), our proposed Split Grid is built with a very simplistic construction scheme which is a major benefit of our approach.Item Progress in Rendering and Modeling for Digital Planetariums(The Eurographics Association, 2010) Magnor, Marcus; Sen, Pradeep; Kniss, Joe; Angel, Edward; Wenger, Stephan; Matthew Cooper and Kari PulliContemporary challenges in the production of digital planetarium shows include real-time rendering realism as well as the creation of authentic content. While interactive, live performance is a standard feature of professional digital-dome planetarium software today, support for physically correct rendering of astrophysical phenomena is still often limited. Similarly, the tools currently available for planetarium show production do not offer much assistance towards creating scientifically accurate models of astronomical objects. Our paper presents recent results from computer graphics research, offering solutions to contemporary challenges in digital planetarium rendering and modeling. Incorporating these algorithms into the next generation of dome display software and production tools will help advance digital planetariums toward make full use of their potential.Item D-NPC: Dynamic Neural Point Clouds for Non-Rigid View Synthesis from Monocular Video(The Eurographics Association and John Wiley & Sons Ltd., 2025) Kappel, Moritz; Hahlbohm, Florian; Scholz, Timon; Castillo, Susana; Theobalt, Christian; Eisemann, Martin; Golyanik, Vladislav; Magnor, Marcus; Bousseau, Adrien; Day, AngelaDynamic reconstruction and spatiotemporal novel-view synthesis of non-rigidly deforming scenes recently gained increased attention. While existing work achieves impressive quality and performance on multi-view or teleporting camera setups, most methods fail to efficiently and faithfully recover motion and appearance from casual monocular captures. This paper contributes to the field by introducing a new method for dynamic novel view synthesis from monocular video, such as casual smartphone captures. Our approach represents the scene as a dynamic neural point cloud, an implicit time-conditioned point distribution that encodes local geometry and appearance in separate hash-encoded neural feature grids for static and dynamic regions. By sampling a discrete point cloud from our model, we can efficiently render high-quality novel views using a fast differentiable rasterizer and neural rendering network. Similar to recent work, we leverage advances in neural scene analysis by incorporating data-driven priors like monocular depth estimation and object segmentation to resolve motion and depth ambiguities originating from the monocular captures. In addition to guiding the optimization process, we show that these priors can be exploited to explicitly initialize our scene representation to drastically improve optimization speed and final image quality. As evidenced by our experimental evaluation, our dynamic point cloud model not only enables fast optimization and real-time frame rates for interactive applications, but also achieves competitive image quality on monocular benchmark sequences. Our code and data are available online https://moritzkappel.github.io/projects/dnpc/.Item Axis-Normalized Ray-Box Intersection(The Eurographics Association and John Wiley & Sons Ltd., 2025) Friederichs, Fabian; Benthin, Carsten; Grogorick, Steve; Eisemann, Elmar; Magnor, Marcus; Eisemann, Martin; Bousseau, Adrien; Day, AngelaRay-axis aligned bounding box intersection tests play a crucial role in the runtime performance of many rendering applications, driven not by complexity but mainly by the volume of tests required. While existing solutions were believed to be pretty much optimal in terms of runtime on current hardware, our paper introduces a new intersection test requiring fewer arithmetic operations compared to all previous methods. By transforming the ray we eliminate the need for one third of the traditional bounding-slab tests and achieve a speed enhancement of approximately 13.8% or 10.9%, depending on the compiler.We present detailed runtime analyses in various scenarios.Item Efficient Perspective-Correct 3D Gaussian Splatting Using Hybrid Transparency(The Eurographics Association and John Wiley & Sons Ltd., 2025) Hahlbohm, Florian; Friederichs, Fabian; Weyrich, Tim; Franke, Linus; Kappel, Moritz; Castillo, Susana; Stamminger, Marc; Eisemann, Martin; Magnor, Marcus; Bousseau, Adrien; Day, Angela3D Gaussian Splats (3DGS) have proven a versatile rendering primitive, both for inverse rendering as well as real-time exploration of scenes. In these applications, coherence across camera frames and multiple views is crucial, be it for robust convergence of a scene reconstruction or for artifact-free fly-throughs. Recent work started mitigating artifacts that break multi-view coherence, including popping artifacts due to inconsistent transparency sorting and perspective-correct outlines of (2D) splats. At the same time, real-time requirements forced such implementations to accept compromises in how transparency of large assemblies of 3D Gaussians is resolved, in turn breaking coherence in other ways. In our work, we aim at achieving maximum coherence, by rendering fully perspective-correct 3D Gaussians while using a high-quality approximation of accurate blending, hybrid transparency, on a per-pixel level, in order to retain real-time frame rates. Our fast and perspectively accurate approach for evaluation of 3D Gaussians does not require matrix inversions, thereby ensuring numerical stability and eliminating the need for special handling of degenerate splats, and the hybrid transparency formulation for blending maintains similar quality as fully resolved per-pixel transparencies at a fraction of the rendering costs. We further show that each of these two components can be independently integrated into Gaussian splatting systems. In combination, they achieve up to 2× higher frame rates, 2× faster optimization, and equal or better image quality with fewer rendering artifacts compared to traditional 3DGS on common benchmarks.