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Item Display Architecture for VLSI -based Graphics Workstations(The Eurographics Association, 1986) Hagen, P. J. W. ten; Kujik, A. A.M.; Trienekens, C. G.; W. StrasserAt present, two popular development areas in computer graphics are improvement ofinteraction behaviour and more realistic graphics.The architecture for a high quality interactive workstation proposed in this work isdesigned such that both demanding and in a sense competing needs can be served.Calculations for generating realistic full 3-D scenes with lighting, transparency,reflection, and refraction effects, are done on the workstation itself. Intermediateresults are stored to locally serve high level interaction mechanisms.Item Adapting Computer Graphics Curricula to Changes in Graphics Technology(The Eurographics Association, 2023) Hitchner, Lewis E.; Sowizral, Henry A.; José Carlos Teixeira; Werner Hansmann; Michael B. McGrathIntroductory computer graphics courses are changing their focus and learning environments. Improvements in hardware and software technology coupled with changes in preparation, interest, and abilities of incoming students are driving the need for curriculum change. Past courses focussed on low- and intermediate-level rendering principies, algorithms, and software development tools. Many of these algorithms have migrated into hardware. Though important knowledge for advanced graphics programmers, most graphics applications programmers have no need to study at this level, much as application programmers have no need to study hardware systems or assembly level programming. Courses need to focus on intermediate- and high-level principies, algorithms, and tools. A fundamental need in modern graphics curricula is integration of a 3D graphics API into the instruction. This paper presents experiences teaching this focus with both low and high level graphics programming API`s . The experiences were gained in courses at an undergraduate university and in multi-day industrial courses for experienced professional programmers.Item Perception of Highlight Disparity at a Distance in Consumer Head-Mounted Displays(ACM Siggraph, 2015) Toth, Robert; Hasselgren, Jon; Akenine-Möller, Tomas; Petrik Clarberg and Elmar EisemannStereo rendering for 3D displays and for virtual reality headsets provide several visual cues, including convergence angle and highlight disparity. The human visual system interprets these cues to estimate surface properties of the displayed environment. Naïve stereo rendering effectively doubles the computational burden of image synthesis, and thus it is desirable to reuse as many computations as possible between the stereo image pair. Computing a single radiance for a point on a surface, to be used when synthesizing both the left and right images, results in the loss of highlight disparity. Our hypothesis is that absence of highlight disparity does not impair perception of surface properties at larger distances. This is due to an ever decreasing angular difference between the surface and the two view points as distance to the surface is increased. The effect is exacerbated by the limited resolution of consumer head-mounted displays. We verify this hypothesis with a user study and provide rendering guidelines to leverage our findings.Item Sarcophagus of the Spouses Installation - Intersection Across Archaeology, 3D Video Mapping and Holographic Techniques Combined with Immersive Narrative Environments and Scenography(IEEE, 2015) Fischnaller, Franz; Guidazzoli, Antonella; Imboden, Silvano; Luca, Daniele De; Liguori, Maria Chiara; Russo, Alfonsina; Lucia, Maria Anna De; Cosentino, Rita; Gabriele Guidi and Roberto Scopigno and Pere BrunetThis paper presents the Sarcophagus of the Spouses installation, an audiovisual performance and exhibit combining 3D video mapping, holographic techniques, computer graphics, high definition visualization with 3D reconstruction and digital storytelling embedded in an immersive narrative environment and scenography. The installation is based on the Sarcophagus of the Spouses (Italian: Sarcofago degli Sposi), a terracotta Etruscan masterpiece of 1.14 m high by 1.9 m wide created around 520 BC depicting a married couple in their last hug, now located in the National Etruscan Museum of Villa Giulia, Rome.Item Enhancing Digital Fabrication with Advanced Modeling Techniques(2017-04) Malomo, Luigi;A few years ago there were only expensive machineries dedicated to rapid prototyping for professionals or industrial application, while nowadays very affordable solutions are on the market and have become useful tools for experimenting, providing access to final users. Given the digital nature of these machine-controlled manufacturing processes, a clear need exists for computational tools that support this new way of productional thinking. For this reason the ultimate target of this research is to improve the easiness of use of such technologies, providing novel supporting tools and methods to ultimately sustain the concept of democratized design (“fabrication for the masses”). In this thesis we present a novel set of methods to enable, with the available manufacturing devices, new cost-effective and powerful ways of producing objects. The contributions of the thesis are three. The first one is a technique that allows to automatically create a tangible illustrative representation of a 3D model by interlocking together a set of planar pieces, which can be fabricated using a 2D laser cutter. The second method allows to automatically design flexible reusable molds to produce many copies of an input digital object. The designs produced by this method can be directly sent to a 3D printer and used to liquid-cast multiple replicas using a wide variety of materials. The last technique is a method to fabricate, using a single-material 3D printer, objects with custom elasticity, and an optimization strategy that, varying the elastic properties inside the volume, is able to design printable objects with a prescribed mechanical behavior.Item Interactive Authoring of 3D Shapes Represented as Programs(Institut Polytechnique de Paris, 2022-07-11) Michel, Élie;Although hardware and techniques have considerably improved over the years at handling heavy content, digital 3D creation remains fairly complex, partly because the bottleneck also lies in the cognitive load imposed over the designers. A recent shift to higher-order representation of shapes, encoding them as computer programs that generate their geometry, enables creation pipelines that better manage the cognitive load, but this also comes with its own sources of friction. We study in this thesis new challenges and opportunities introduced by program-based representations of 3D shapes in the context of digital content authoring. We investigate ways for the interaction with the shapes to remain as much as possible in 3D space, rather than operating on abstract symbols in program space. This includes both assisting the creation of the program, by allowing manipulation in 3D space while still ensuring a good generalization upon changes of the free variables of the program, and helping one to tune these variables by enabling direct manipulation of the output of the program. We explore diversity of program-based representations, focusing various paradigms of visual programming interfaces, from the imperative directed acyclic graphs (DAG) to the declarative Wang tiles, through more hybrid approaches. In all cases we study shape programs that evaluate at interactive rate, so that they fit in a creation process, and we push this by studying synergies of program-based representations with real time rendering pipelines. We enable the use of direct manipulation methods on DAG output thanks to automated rewriting rules and a non-linear filtering of differential data. We help the creation of imperative shape programs by turning geometric selection into semantic queries and of declarative programs by proposing an interface-first editing scheme for authoring 3D content in Wang tiles. We extend tiling engines to handle continuous tile parameters and arbitrary slot graphs, and to suggest new tiles to add to the set. We blend shape programs into the visual feedback loop by delegating tile content evaluation to the real-time rendering pipeline or exploiting the program's semantics to drive an impostor-based level-of-details system. Overall, our series of contributions aims at leveraging program-based representations of shapes to make the process of authoring 3D digital scenes more of an artistic act and less of a technical task.Item 3D scene analysis through non-visual cues(University College London, 2019-10-06) Monszpart, Aron;The wide applicability of scene analysis from as few viewpoints as possible attracts the attention of many scientific fields, ranging from augmented reality to autonomous driving and robotics. When approaching 3D problems in the wild, one has to admit, that the problems to solve are particularly challenging due to a monocular setup being severely under-constrained. One has to design algorithmic solutions that resourcefully take advantage of abundant prior knowledge, much alike the way human reasoning is performed. I propose the utilization of non-visual cues to interpret visual data. I investigate, how making non-restrictive assumptions about the scene, such as “obeys Newtonian physics” or “is made by or for humans” greatly improves the quality of information retrievable from the same type of data. I successfully reason about the hidden constraints that shaped the acquired scene to come up with abstractions that represent likely estimates about the unobservable or difficult to acquire parts of scenes. I hypothesize, that jointly reasoning about these hidden processes and the observed scene allows for more accurate inference and lays the way for prediction through understanding. Applications of the retrieved information range from image and video editing (e.g., visual effects) through robotic navigation to assisted living.