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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Platform Independent Real-Time X3D Shaders and their Applications in Bioinformatics Visualization

Liu, Feng 12 January 2007 (has links)
Since the introduction of programmable Graphics Processing Units (GPUs) and procedural shaders, hardware vendors have each developed their own individual real-time shading language standard. None of these shading languages is fully platform independent. Although this real-time programmable shader technology could be developed into 3D application on a single system, this platform dependent limitation keeps the shader technology away from 3D Internet applications. The primary purpose of this dissertation is to design a framework for translating different shader formats to platform independent shaders and embed them into the eXtensible 3D (X3D) scene for 3D web applications. This framework includes a back-end core shader converter, which translates shaders among different shading languages with a middle XML layer. Also included is a shader library containing a basic set of shaders that developers can load and add shaders to. This framework will then be applied to some applications in Biomolecular Visualization.
32

Analysis and exploration of virtual 3D city models using 3D information lenses

Trapp, Matthias January 2007 (has links)
This thesis addresses real-time rendering techniques for 3D information lenses based on the focus & context metaphor. It analyzes, conceives, implements, and reviews its applicability to objects and structures of virtual 3D city models. In contrast to digital terrain models, the application of focus & context visualization to virtual 3D city models is barely researched. However, the purposeful visualization of contextual data of is extreme importance for the interactive exploration and analysis of this field. Programmable hardware enables the implementation of new lens techniques, that allow the augmentation of the perceptive and cognitive quality of the visualization compared to classical perspective projections. A set of 3D information lenses is integrated into a 3D scene-graph system: • Occlusion lenses modify the appearance of virtual 3D city model objects to resolve their occlusion and consequently facilitate the navigation. • Best-view lenses display city model objects in a priority-based manner and mediate their meta information. Thus, they support exploration and navigation of virtual 3D city models. • Color and deformation lenses modify the appearance and geometry of 3D city models to facilitate their perception. The presented techniques for 3D information lenses and their application to virtual 3D city models clarify their potential for interactive visualization and form a base for further development. / Diese Diplomarbeit behandelt echtzeitfähige Renderingverfahren für 3D Informationslinsen, die auf der Fokus-&-Kontext-Metapher basieren. Im folgenden werden ihre Anwendbarkeit auf Objekte und Strukturen von virtuellen 3D-Stadtmodellen analysiert, konzipiert, implementiert und bewertet. Die Focus-&-Kontext-Visualisierung für virtuelle 3D-Stadtmodelle ist im Gegensatz zum Anwendungsbereich der 3D Geländemodelle kaum untersucht. Hier jedoch ist eine gezielte Visualisierung von kontextbezogenen Daten zu Objekten von großer Bedeutung für die interaktive Exploration und Analyse. Programmierbare Computerhardware erlaubt die Umsetzung neuer Linsen-Techniken, welche die Steigerung der perzeptorischen und kognitiven Qualität der Visualisierung im Vergleich zu klassischen perspektivischen Projektionen zum Ziel hat. Für eine Auswahl von 3D-Informationslinsen wird die Integration in ein 3D-Szenengraph-System durchgeführt: • Verdeckungslinsen modifizieren die Gestaltung von virtuellen 3D-Stadtmodell- Objekten, um deren Verdeckungen aufzulösen und somit die Navigation zu erleichtern. • Best-View Linsen zeigen Stadtmodell-Objekte in einer prioritätsdefinierten Weise und vermitteln Meta-Informationen virtueller 3D-Stadtmodelle. Sie unterstützen dadurch deren Exploration und Navigation. • Farb- und Deformationslinsen modifizieren die Gestaltung und die Geometrie von 3D-Stadtmodell-Bereichen, um deren Wahrnehmung zu steigern. Die in dieser Arbeit präsentierten Techniken für 3D Informationslinsen und die Anwendung auf virtuelle 3D Stadt-Modelle verdeutlichen deren Potenzial in der interaktiven Visualisierung und bilden eine Basis für Weiterentwicklungen.
33

Radar and sea clutter simulation with Unity 3D game engine / Simulering av radar och sjöklotter med Unity 3D-spelmotor

Johnsson, Mikael, Bergman, Linus January 2023 (has links)
Game engines are well known for their use in the gaming industry but are starting to have an impact in other areas as well. Architecture, automotive, and the defence industry are today using these engines to visualise and, to some extent, test their products. In this thesis, we have examined how the game engine Unity could be used for simulating a radar with the purpose of detecting and measuring sea clutter. Following a pre-study examining different implementation approaches, it was decided to use ray tracing. The radar itself is simulated by using the camera to emit rays and having a plane object directly behind it act as a receiver. Rays are then individually traced for each pixel, propagating throughout the scene and saving information such as hit coordinates, distance travelled, and direction. By using the total travel distance of each ray that returned to the receiver, the phase of each ray is calculated. This is then used to compute the total amplitude, which represents the returned signal strength. Using a compute shader, most of the computations are done in parallel on the GPU, enabling millions of rays to be traced. As measuring sea clutter was an objective of the study, tests measuring the ocean were carried out. These used ocean surfaces with two different sea states, using the Phillips spectrum to generate realistic waves. A ship object was then tested in free space and on two different ocean surfaces. The calculated amplitude and the number of rays returned were used to determine the signal strength returned and the RCS of the object. The purpose of this was to compare with other results of sea clutter studied, observed both in the real world and in simulated scenarios, and determine if our approach could be a valid choice for the industry. Some results matched the findings of a similar study that used a professional radar simulation tool called OKTAL. Other results of sea clutter were found to not be realistic due to certain limitations. The current main limitation of our implementation is not being able to trace a large enough ocean surface with the finer details needed for realistic results. However, this could be solved by creating a better implementation. These findings suggest that simulating radar and sea clutter in Unity is a feasible approach worth continuing to explore. / Spelmotorer är välkända för sin användning inom spelindustrin men har också fått genomslag inom andra områden. Arkitektur, fordonsindustrin och försvarsindustrin använder idag dessa verktyg för att visualisera och till viss mån, även testa sina produkter. I detta examensarbete har vi undersökt hur spelmotorn Unity kan användas för att simulera en radar i syfte att detektera och mäta sjöklotter. Efter en förstudie där olika implementeringsmetoder undersöktes, beslutades det att använda strålspårning (eng. ray tracing). Själva radarn simuleras genom att använda kameraobjektet i Unity för att sända ut strålar. Bakom kameran finns ett planobjekt som fungerar som mottagare. Strålar spåras sedan individuellt för varje pixel och sprider sig genom en given scen. Samtidigt sparas information såsom träffkoordinater, den totala färdsträckan samt riktning. Genom att använda det totala färdavståndet för varje stråle som återvänt till mottagaren kan fasen för varje stråle beräknas. Detta kan sedan användas för att beräkna den totala returnerade amplituden, vilket motsvarar den returnerade signalstyrkan. Med hjälp av en "compute shader" kan databeräkningarna göras parallellt av GPU:n vilket underlättar när så många strålar ska spåras. Eftersom syftet med uppsatsen var mätning av simulerat sjöklotter, genomfördes tester för att mäta på ett simulerat hav. Havsytorna hade två olika sjöstadier, vilka genererades med Phillips-spektrumet för att få realistiska vågor. Ett fartygsobjekt testades sedan i frirymd och sedan även i de två olika havsytorna. Amplituden och mängden strålar som returnerades användes för att bestämma den totala returnerade signalstyrkan och "Radar Cross Section" (RCS) för objektet. Syftet med detta var att kunna jämföra med andra studier gällande sjöklotter, både simulerade som verklighetsbaserade och avgöra om vårt tillvägagångssätt kunde resultera i ett användbart verktyg för branschen. De olika amplituder och antalet strålar som vi fick tillbaka varierade beroende på vilka vinklar och havsytor som användes.Vissa resultat var inte realistiska jämfört med verkliga mätningar av sjöklotter. Det beror främst på våra nuvarande begränsningar i att inte kunna spåra en tillräckligt stor och tillräckligt detaljerad havsyta, vilket behövs för att mätningarna ska vara mer realistiska. Däremot matchade vi några resultat med de från en liknande studie, där verktyget OKTAL, som är ett professionellt radarsimuleringsverktyg, användes. Detta i kombination med möjligheterna för en förbättrad implementation tyder på att användningen av en spelmotor som Unity är ett intressant verktyg värd att vidareutforska radarsimuleringar med.
34

Real-time Terrain Deformation with Isosurface Algorithms

Nässén, Olle, Leiborn, Edvard January 2019 (has links)
Background. Being able to modify virtual environments can create immersive experiences for video-game players. Storing data as volumetric scalar fields allows for highly modifiable 3D environments that can be converted into GPU-friendly triangles with isosurface algorithms. Using scalar fields and isosurface algorithms can be more computationally expensive and require more data than the more commonly used polygonal models. Objectives. The aim of this thesis is to explore solutions to modifying real-time 3D environments with isosurface algorithms. This will be done in two parts. First in terms of observing how modern games deal with storing scalar fields, researching which isosurface algorithms are being used and how they are being used in games. The second part is to create an application and limit the data storage required while still running at a real-time speed. Methods. There are two methods to achieve the aim. The first is to research and see which data structures and isosurface algorithms are being used in modern games and how they are utilized. The second method will be done by implementation. The implementation will use the GPU through compute shaders and use marching cubes as isosurface algorithm. It will utilize Christopher Dyken’s Histogram Pyramids for stream compaction. Two different versions will be implemented that differ in terms of what data types will be used for storage. The first using the data type char and the second int. Between these two versions, the runtime speed will be measured and compared on two different hardware configurations. Results. Finding good data on what algorithms games use is difficult. Modern games are using scalar fields in many different ways: Some allow almost complete modification of terrain, others only use it for a 3D environment. For data storage, octrees and chunks are two common ways to store the fields. Dual Contouring appears to be the primary isosurface algorithm being used based on the researched games. The results of the implementation were very fast and usable in real time environments for destruction of terrain on a large scale. The less storage intensive variation of this implementation(char) gave faster results on modern hardware but the opposite(int) was true on older hardware. Conclusions. Modifying scalar field terrain is done at a very large scale in modern games. The choice of using Dual Contouring or Marching Cubes depends on the use-case. For areas where sharp features can be important Dual Contouring is the preferred choice. Likely for these reasons Dual Contouring was found to be a popular choice in the studied games. For other areas, like many types of terrain, Marching Cubes is very fast, as can be seen in the implementation. By using the char version of the implementation, interacting with the environment in real-time is possible at high frame-rates.
35

Lovefish : en polityr för icke-realistisk rendering i texturerade skuggtoner med Newtek Lightwave3D / Lovefish : a shader for non-realistic rendering with textured tones in Newtek Lightwave3D

Esbjörnsson, Jimmy January 2004 (has links)
<p>The aim with this thesis is to develop a plugin; Lovefish, for the purpose of allowing non-realistic renderings (NPR) for visualisation in Newtek Lightwave3D. The main purpose with Lovefish is to offer textured tones, something that has not been offered before by any previously existing shader for Lightwav3D. The textured tones are a substantially widening of what is possible to imitate in the field of classical art techniques. Among others has a number of SIGGRAPH papers has been the foundation and a source of inspiration for what has been achieve in this project. Further has this thesis treated a number of questions: what is non-photorealistic rendering is and how it works; an overview of the Lightwave3Ds software development kit (SDK).</p>
36

Lovefish : en polityr för icke-realistisk rendering i texturerade skuggtoner med Newtek Lightwave3D / Lovefish : a shader for non-realistic rendering with textured tones in Newtek Lightwave3D

Esbjörnsson, Jimmy January 2004 (has links)
The aim with this thesis is to develop a plugin; Lovefish, for the purpose of allowing non-realistic renderings (NPR) for visualisation in Newtek Lightwave3D. The main purpose with Lovefish is to offer textured tones, something that has not been offered before by any previously existing shader for Lightwav3D. The textured tones are a substantially widening of what is possible to imitate in the field of classical art techniques. Among others has a number of SIGGRAPH papers has been the foundation and a source of inspiration for what has been achieve in this project. Further has this thesis treated a number of questions: what is non-photorealistic rendering is and how it works; an overview of the Lightwave3Ds software development kit (SDK).
37

Bus Interface Design Between Different Clock Domains and Its Application to OpenGL-ES 2.0 3D Graphics Systems

Lin, Chi-Guang 26 July 2011 (has links)
Asynchronous bus interface units to AMBA AHB are designed so that an OpenGL ES 2.0 vertex shader can communicate with other hardware units via AHB bus under different working frequencies. The first design is to directly implement an asynchronous AHB wrapper for the vertex shader. The other two designs are based on Open Core Protocol (OCP) to allow for more flexibility. The hardware intellectual property (IP), vertex shader in this thesis, to OCP asynchronous unit is designed so that the IP can be developed independently with different bus protocols as long as the OCP-to-bus interface is provided for a particular bus protocol. With the help of asynchronous IP-to-OCP and OCP-to-AHB interface units, the vertex shader IP can operate at different frequencies from the AHB bus. Furthermore, the same vertex shader (VS) can be connected to other bus protocol (such as AXI) of different frequencies if the OCP-to-AXI interface is provided because the the asynchronous VS-to-OCP have been designed in this thesis.
38

Design of a Multi-Core Multi-thread Floating-Point Processor and Its Application in Computer Graphics

Yeh, Chia-Yu 06 September 2011 (has links)
Graphics processing unit (GPU) designs usually adopts various computer architecture techniques to boost the computation speed, including single-instruction multiple data (SIMD), very-long-instruction word (VLIW), multi-threading, and/or multi-core. In OpenGL ES 2.0, user programmable vertex shader (VS) hardware unit can be designed using vectored SIMD computation unit so that it can efficiently compute the matrix-vector multiplication, one of the key operations in vertex transformation. Recently, high-performance GPU, such as Telsa series from nVidia, is designed with many-core architectures with each core responsible for scalar operations. The intention is to allow for efficient execution of general-purpose computations in addition to the specialized graphics computations. In this thesis, we design a scalar-based multi-threaded GPU design that is composed of four scalar processors, one special-function unit, and can execute multi-threaded instructions. We use the example of vertex transformation to demonstrate execution efficiency of the scalar-based multi-threaded GPU. We also make comparison with the vector-based SIMD GPU.
39

A comparison between techniques for color grading in games

Oldenborg, Mattias January 2006 (has links)
<p>Color has been significant in visual arts for as long as the art-forms have existed. Still images and movies have long used colors and color grading effects to affect the viewer and characterize the work. In recent years attempts have been made to bring these techniques of stylizing also to interactive games. This dissertation aims to compare two different approaches of performing real-time color grading for games. Focus is put on examining the two ways from a number of different perspectives and from there draw conclusions on advantages and disadvantages of the approaches. The results show no unanimously superior approach but rather aim to break down the results in categories and attempt to explain the benefits and drawbacks in using either one of them, aiding the decision for anyone inclined to implement color grading effects in games.</p>
40

High Fidelity Virtual Environments: Does Shader Quality or Higher Polygon Count Models Increase Presence and Learning

January 2014 (has links)
abstract: This research study investigated the effects of high fidelity graphics on both learning and presence, or the "sense of being there," inside a Virtual Learning Environment (VLE). Four versions of a VLE on the subject of the element mercury were created, each with a different combination of high and low fidelity polygon models and high and low fidelity shaders. A total of 76 college age (18+ years of age) participants were randomly assigned to one of the four conditions. The participants interacted with the VLE and then completed several posttest measures on learning, presence, and attitudes towards the VLE experience. Demographic information was also collected, including age, computer gameplay experience, number of virtual environments interacted with, gender and time spent in this virtual environment. The data was analyzed as a 2 x 2 between subjects ANOVA. The main effects of shader fidelity and polygon fidelity were both non- significant for both learning and all presence subscales inside the VLE. In addition, there was no significant interaction between shader fidelity and model fidelity. However, there were two significant results on the supplementary variables. First, gender was found to have a significant main effect on all the presence subscales. Females reported higher average levels of presence than their male counterparts. Second, gameplay hours, or the number of hours a participant played computer games per week, also had a significant main effect on participant score on the learning measure. The participants who reported playing 15+ hours of computer games per week, the highest amount of time in the variable, had the highest score as a group on the mercury learning measure while those participants that played 1-5 hours per week had the lowest scores. / Dissertation/Thesis / Doctoral Dissertation Educational Technology 2014

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