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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.
71

Ålderns betydelse inom animation : En studie om människans upplevelse av 3D-karaktärers ålder i förhållande till rörelse

Johansson, Martin January 2010 (has links)
Arbetet handlar om ålderns betydelse inom animation och om det är en av faktorerna till varför effekten "The Uncanny Valley" uppstår. Det praktiska arbetet inkluderar skapandet av fyra olika karaktärer, ung kvinna, ung man, äldre kvinna och äldre man. Karaktärerna animerades utefter fyra mänskliga referenser i form av en gammal och en ung rörelse för respektive kön. Varje karaktär utförde både den gamla och den unga rörelsen och det gav sedan grunden till en enkätundersökning med 51 respondenter där betraktaren fick undersöka de åtta animationerna och svara på frågor/påståenden i ett frågeformulär. Resultatet av undersökningen visade att åldern är en av flera faktorer till "The Uncanny Valley", men där den utseendemässiga åldern har betydelse istället för den rörelsemässiga åldersskillnaden som jag först hade föreställt mig.
72

Analyse des processus de recherche et de modélisation du patrimoine à partir de deux cas : l’écluse Saint-Gabriel du canal de Lachine et la gare Montreal and Southern Counties Railways Co.

Gosselin, Louis Pierre January 2014 (has links)
Depuis deux décennies, des chercheurs et des diffuseurs utilisent des modélisations 3D pour rendre compte d'espaces et de structures du passé. Cependant, les historiens demeurent généralement réticents envers cette manière de représenter l'histoire. Pourtant, la science historique peut tirer parti du 3D de plusieurs façons. Une modélisation peut servir de laboratoire, une approche déjà utilisée en archéologie. Par exemple, à partir d'un modèle 3D du Colisée, les historiens pourraient s'intéresser aux interactions entre la population romaine et le bâtiment, aux techniques de construction, à l'impact de cette architecture monumentale sur l'évolution urbaine. La modélisation ne doit pas non plus se limiter aux grands monuments du passé. L'évolution de l'architecture vernaculaire, d'un quartier populaire, d'un complexe industriel ou d'un village aborigène peut tout aussi bien se prêter à une analyse tirant profit d'une modélisation. Mais avant d'intégrer une telle approche à la discipline historique, il faut assurer les chercheurs du caractère scientifique d'une maquette 3D. Un tel environnement doit pouvoir répondre aux mêmes critères scientifiques que toute autre production historique de nature académique. De tels systèmes – incorporant des objets virtuels, des sources et des éléments narratifs – sont présentement en développement, et je porterai donc mon attention sur l'élaboration d'une procédure efficace pour créer des environnements virtuels pertinents respectant les pratiques historiennes.
73

Point-of-gaze estimation in three dimensions

Hennessey, Craig 11 1900 (has links)
Binocular eye-gaze tracking can be used to estimate the point-of-gaze (POG) of a subject in real-world three-dimensional (3D) space using the vergence of the eyes. In this thesis, a novel non-contact, model-based technique for 3D POG estimation is presented. The non-contact system allows people to select real-world objects in 3D physical space using their eyes, without the need for head-mounted equipment. Using a model-based POG estimation algorithm allows for free head motion and a single stage of calibration. The users were free to naturally move and reorient their heads while operating the system, within an allowable headspace of 3.2 x 9.2 x 14 cm. A rela tively high precision, as measured by the standard deviation of the 3D POG estimates, was measured to be 0.26 cm and was achieved with the use of high speed sampling and digital filtering techniques. When observing points in a 3D volume, large head and eye rotations are far more common than when observing a 2D screen. A novel corneal reflection pattern matching algorithm is presented for increasing image feature tracking reliability in the presence of large eye rotations. It is shown that an average accuracy of 3.93 cm was achieved over seven different subjects and a workspace volume of 30 x 23 x 25 cm (width x height x depth). An example application is presented illustrating the use of the 3D POG as a human computer interface in a 3D game of Tic-Tac-Toe on a 3 x 3 x 3 volumetric display.
74

Evaluating Textual Annotations with Interactive 3D Models

Gupta, Ankur 03 March 2013 (has links)
Annotations play a key role in explaining and elaborating 3D illustrations. They support users in identifying and establishing a visual link between different components within a 3D model. However, one major issue with annotating 3D illustrations is that there are no standard guidelines that clearly define which annotation type or style to use or is preferred by users in supporting learning and identifying objects at different zooming levels. Often, the decision of which style to use is influenced by size of the components being annotated and the overall look and feel (i.e., reduced occlusion and visual clutter) of the annotated view in display. In our research, we try to understand how effectively the three types of textual annotation labels (internal, external, and annotation boxes) can support users in learning, identifying, and navigating through 3D objects. We report the results of a study that evaluates the efficiency and accuracy in searching for components inside a 3D model, measures the impact on learning (in recalling the names of various components and their locations), and analyzes for user preferences in interacting with a 3D model on a mobile form factor at different zooming levels. Results of our study reflect that participants preferred external style annotations over internal and box style annotations, and that the participant’s performance (for both efficiency and accuracy) in searching for components inside a 3D model was highest with external style annotations. We also found that participants recalled more components when annotated with external styles annotations. Our findings suggest that of the three textual annotation styles considered in this study, external style annotation is the best annotation style to use in an annotated 3D model. / Annotations play a key role in explaining and elaborating 3D illustrations. They support users in identifying and establishing a visual link between different components within a 3D model. However, one major issue with annotating 3D illustrations is that there are no standard guidelines that clearly define which annotation type or style to use or is preferred by users in supporting learning and identifying objects at different zooming levels. Often, the decision of which style to use is influenced by size of the components being annotated and the overall look and feel (i.e., reduced occlusion and visual clutter) of the annotated view in display. In our research, we try to understand how effectively the three types of textual annotation labels (internal, external, and annotation boxes) can support users in learning, identifying, and navigating through 3D objects. We report the results of a study that evaluates the efficiency and accuracy in searching for components inside a 3D model, measures the impact on learning (in recalling the names of various components and their locations), and analyzes for user preferences in interacting with a 3D model on a mobile form factor at different zooming levels. Results of our study reflect that participants preferred external style annotations over internal and box style annotations, and that the participant’s performance (for both efficiency and accuracy) in searching for components inside a 3D model was highest with external style annotations. We also found that participants recalled more components when annotated with external styles annotations. Our findings suggest that of the three textual annotation styles considered in this study, external style annotation is the best annotation style to use in an annotated 3D model.
75

TZee: a tangible device for 3d interactions on tabletop computers

Williams, Cary 07 May 2011 (has links)
Manipulating 3D objects on a tabletop computer is inherently problematic. The flat surface of tabletop computers enable natural 2D interaction, but lack the additional dimension needed to intuitively facilitate 3D object manipulation. In this thesis I present TZee, a passive tangible widget that enables natural interactions with 3D objects by exploiting the lighting properties of diffuse illumination (DI) multi-touch tabletops. The Tangible User Interface (TUI), TZee is constructed from several pieces of stacked acrylic glass. The stacked glass enables TZee to channel the light emitted from the tabletop slightly higher above the surface without major light loss. This technique allows the tangible interface to transmit touches on the device to the tabletop without any supplementary power. TZee enables simple translation, rotation and scaling along the x, y, or z axes. This thesis discusses several important design considerations of TZee, demonstrated TZee’s value though several applications and a gesture design study.
76

3D-scanning : Volymberäkning vid scanning av bergvägg / 3D-scanning : Volume calculation when scanning a rock wall

Svahn, Stefan January 2014 (has links)
Scanning är ett verktyg som har utvecklats mycket och används mer och mer inom geodetisk mätning. Instrumenten har blivit mer pålitliga med högre kvalité på resultaten, därför är det viktigt att eliminera de problem som kan skada scanningens pålitlighet. Det problemet som ska undersökas och testas i det här examensarbetet uppstår när man till exempel scannar en bergvägg. Man vill få en så lik avbildning av bergväggen som möjligt för att sedan kunna göra volymberäkningar emot bergväggen. Avbildningen av bergväggen består av ett moln av punkter som tillsammans skapar en 3D-modell av bergväggen.   Om det ska fyllas med betong emot bergväggen så måste man veta vilken volym betong det kommer gå åt, därför är det viktigt att modellen av bergväggen stämmer. Problemet är att modellen kan visa sig att vara fel beroende på hur man har scannat. Det är när bergväggen är så pass ojämn och att man inte kan scanna från alla vinklar som det uppstår så kallade skuggor i modellen, en hålighet i berget kan då i modellen istället vara fylld. Detta gör att det går åt mer volym när man ska fylla igen vilket kan bli dyrt för alla inblandade.   För att testa detta ska flera olika metoder testas under arbetet, olika typer av instrument, täthet mellan punkter, olika infallsvinklar och manuell scanning. Det som är intressant att se är hur pass mycket metoderna skiljer sig mellan varandra och genom att jämföra dessa så kan man få fram ett resultat som visar vilken metod som är mest trovärdig.   Arbetets resultat och analys finns att läsa senare i den här rapporten där man också får svar hur arbetet genomfördes och hur metoderna skilde sig emot varnadra.
77

Exemplar-based image inpainting on the GPU applied to 3D video conversion

Wallace, Ryan 22 February 2012 (has links)
My thesis investigates automation and optimizations for occlusion filling, a problem resulting from the generation of new viewpoints in the 3D video conversion process. Image inpainting is a popular topic in image processing research. The ability to fill a region of an image in a manner that is visually pleasing is a difficult and computationally expensive task. Recently, the most successful methods have been exemplar-based, copying patches of the image from a specified source region into the region to be filled. These algorithms are designed to propagate both structure and texture into the fill region. They are brute force algorithms however, and are generally implemented as sequential algorithms to be run on the CPU. In this research, I have effectively mapped the costly portions of an exemplar-based image inpainting algorithm to the GPU. I produce equivalent inpainting results in less time by parallelizing the brute force patch searching portion of the algorithm. Furthermore, I compare the results with another recent, optimized inpainting algorithm, and apply both algorithms to the real world problem of occlusion filling in a 3D video conversion pipeline. / Graduate / 10000-01-01
78

Optimization of 3D Game Models : A qualitative research study in Unreal Development Kit

Lohikoski - Håkansson, Laura, Rudén, Elin January 2013 (has links)
Our goal with this study is to examine how much optimization of 3D game models can affect the overall performance of a game. After a previous pilot study we decided on use a method where we worked with a 3D scene which was made earlier unconnected to this study. We created two versions of the scene in Unreal Development Kit, one with none of the meshes optimized and the second scene where the meshes are optimized. From these two scenes we wrote down the different stats: the draw calls, frame rate, millisecond per frame and visible static mesh elements as well as the memory usage. Comparing these stats from the two scenes, we found that there was a change in the stats. Draw calls and frame rate had dropped in the second scene, as well as the memory usage which made the game run more smoothly without losing much of its aesthetic quality. / Målet med vår studie var att se hur stor skillnad optimering av 3D-modeller i spel gör för att förbättra spelprestandan. Efter att ha utfört en pilotstudie beslutade vi oss för att använda en tidigare byggd 3D-scen för undersökningen i vår C-uppsats. Vi skapade två versioner av scenen i Unreal Development Kit, en där inga modeller var optimerade och den andra där vi optimerat modellerna. Vi skrev därefter ner statistik från de olika scenerna, nämligen draw calls, frame rate, millisecond per frame och visible static mesh elements liksom minnesanvändning. Efter att ha jämfört resultaten såg vi att det fanns en väsentlig skillnad mellan scenerna prestandamässigt. Både draw calls, frame rate och minnesanvändningen hade minskat efter optimeringen vilket ledde till att spelet kördes smidigare.
79

3D nonlinear mixed finite-element analysis of RC beams and plates with and without FRP reinforcement

Hoque, Mohammad M. 05 April 2006 (has links)
Three 3D nonlinear finite-element (FE) models are developed to study the behavior of concrete beams and plates with and without externally reinforcement of fibre reinforced polymer (FRP). Ramtekkar’s mixed layer-wise 3 dimensional (3D) 18-node FE model (108 degrees-of-freedom, DOFs) is modified to accommodate the nonlinear concrete and elasto-plastic steel behaviour. Saenz’s stress-strain equation is used for material nonlinearity of concrete. As in any 3D mixed FE analysis, the run time using the model can be computationally expensive. Two additional layer-wise 18-node FE models: Displacement FE model (54 DOF) and transitional FE model (81 DOF) are developed. The displacement FE model is based on purely displacement field, i.e. only displacement components are enforced throughout the thickness of the structures. The transitional FE model has six DOF (three displacement components in the coordinate axis direction and three transverse stress components - where z is the thickness direction) per node in the upper surface and only three DOF (three displacement components in the coordinate axis direction) per node in the bottom surface.The analysis of reinforced concrete (RC) beam strengthened with FRP and composite plate using these models are verified against the experimental results and the results from the commercial software, ANSYS respectively. Several parametric studies are done on composite RC beam and composite plate.
80

TZee: a tangible device for 3d interactions on tabletop computers

Williams, Cary 07 May 2011 (has links)
Manipulating 3D objects on a tabletop computer is inherently problematic. The flat surface of tabletop computers enable natural 2D interaction, but lack the additional dimension needed to intuitively facilitate 3D object manipulation. In this thesis I present TZee, a passive tangible widget that enables natural interactions with 3D objects by exploiting the lighting properties of diffuse illumination (DI) multi-touch tabletops. The Tangible User Interface (TUI), TZee is constructed from several pieces of stacked acrylic glass. The stacked glass enables TZee to channel the light emitted from the tabletop slightly higher above the surface without major light loss. This technique allows the tangible interface to transmit touches on the device to the tabletop without any supplementary power. TZee enables simple translation, rotation and scaling along the x, y, or z axes. This thesis discusses several important design considerations of TZee, demonstrated TZee’s value though several applications and a gesture design study.

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