Snö påverkas av en stor mängd aspekter i verkligheten, och verklighetstrogen simulering av snö är resurskrävande. För att förbättra resursåtgången i applikationer simuleras snö på olika sätt beroende på det önskade resultatet. I denna studie undersöks bildfrekvensen i en heuristisk baserad implementation, med målet att ta reda på hur mycket bildfrekvensen påverkas av vilka aspekter som simuleras. Undersökningen utfördes med hjälp av en tredimensionell bergsmiljö, riktad mot användning i realtid. Aspekter som påverkar snösimulering delas in i tre delar, Snösmältning, Nederbörd, samt Förflyttning av snö. Flera utvärderingar utfördes på olika varianter av artefakten, där bildfrekvensen mättes. Utvärderingarna visade ingen märkbar skillnad i bildfrekvens beroende på vilka aspekter som simuleras. Tydliga förändringar uppstod om texturupplösning och polygonantal modifierades istället.

<p>To give a realistic impression in a driving simulator for nighttime driving, there are many challenging aspects to consider. One of the most important aspects is the illumination caused by the headlights of the own vehicle. To give a realistic impression there is the need to consider the characteristics of the headlight in use to be able to represent main and dipped beam, but also to represent different models and types of headlights. </p><p>Another important aspect is the dazzling effects caused by the light cast by other vehicles upon the driver. These effects are not only important to give a realistic and visually appealing simulation, but also to simulate blinding effects which may affect the drivers ability to perceive the traffic environment to a large degree. </p><p>This thesis describes methods to simulate these vital aspects of night-drive simulation in real-time using the capabilities of today's graphics cards.</p>

<p>En realistisk simulation kräver att alla simulerade objekten ska interaktivt och dynamiskt animeras. Delar av objektens kropp ska deformeras och andra delar ska sönderfalla vid en krock med ett annat objekt. De flesta 3d applikationer har som gemensamt vissa tekniker som används vid dynamiska simulationer. Tyvärr så finns det inte en smidig och snabb teknik för att deformera solida objekt vid kollisioner, detta gäller även Maya som jag använde i detta arbete. Detta arbete ska visa en smidig teknik att deformera vissa delar av en komplicerad modell och få andra delar att splittras och spridas i en dynamisk simulation som är både fysiskt rätt och ser visuellt bra ut. Resultatet är en kort animationsfilm som visar teknikerna i praktiken. Enskilda användare av 3Dapplikationer exempelvis studenter kommer ha nytta av arbetets olika delmoment och kan hänvisa till informationen.</p>

To give a realistic impression in a driving simulator for nighttime driving, there are many challenging aspects to consider. One of the most important aspects is the illumination caused by the headlights of the own vehicle. To give a realistic impression there is the need to consider the characteristics of the headlight in use to be able to represent main and dipped beam, but also to represent different models and types of headlights. Another important aspect is the dazzling effects caused by the light cast by other vehicles upon the driver. These effects are not only important to give a realistic and visually appealing simulation, but also to simulate blinding effects which may affect the drivers ability to perceive the traffic environment to a large degree. This thesis describes methods to simulate these vital aspects of night-drive simulation in real-time using the capabilities of today's graphics cards.

To aid diagnosis, treatment planning, and patient education, clinicians require tools to anal- yse and explore the increasingly large three-dimensional (3-D) datasets generated by modern medical scanners. Direct volume rendering is one such tool finding favour with radiologists and surgeons for its photorealistic representation. More recently, volume illustration — or non-photorealistic rendering (NPR) — has begun to move beyond the mere depiction of data, borrowing concepts from illustrators to visually enhance desired information and suppress un- wanted clutter. Direct volume rendering generates images by accumulating pixel values along rays cast into a 3-D image. Transfer functions allow users to interactively assign material properties such as colour and opacity (a process known as classification). To achieve real-time framerates, the rendering must be accelerated using a technique such as 3-D texture mapping on commod- ity graphics processing units (GPUs). Unfortunately, current methods do not allow users to intuitively enhance regions of interest or suppress occluding structures. Furthermore, addi- tional scalar images describing clinically relevant measures have not been integrated into the direct rendering method. These tasks are essential for the effective exploration, analysis, and presentation of 3-D images. This body of work seeks to address the aforementioned limitations. First, to facilitate the research program, a flexible architecture for prototyping volume illustration methods is pro- posed. This program unifies a number of existing techniques into a single framework based on 3-D texture mapping, while also providing for the rapid experimentation of novel methods. Next, the prototyping environment is employed to improve an existing method—called tagged volume rendering — which restricts transfer functions to given spatial regions using a number of binary segmentations (tags). An efficient method for implementing binary tagged volume rendering is presented, along with various technical considerations for improving the classifi- cation. Finally, the concept of greyscale tags is proposed, leading to a number of novel volume visualisation techniques including position modulated classification and dynamic exploration. The novel methods proposed in this work are generic and can be employed to solve a wide range of problems. However, to demonstrate their usefulness, they are applied to a specific case study. Ischaemic heart disease, caused by narrowed coronary arteries, is a leading healthconcern in many countries including Australia. Computed tomography angiography (CTA) is an imaging modality which has the potential to allow clinicians to visualise diseased coronary arteries in their natural 3-D environment. To apply tagged volume rendering for this case study, an active contour method and minimal path extraction technique are proposed to segment the heart and arteries respectively. The resultant images provide new insight and possibilities for diagnosing and treating ischaemic heart disease.

En realistisk simulation kräver att alla simulerade objekten ska interaktivt och dynamiskt animeras. Delar av objektens kropp ska deformeras och andra delar ska sönderfalla vid en krock med ett annat objekt. De flesta 3d applikationer har som gemensamt vissa tekniker som används vid dynamiska simulationer. Tyvärr så finns det inte en smidig och snabb teknik för att deformera solida objekt vid kollisioner, detta gäller även Maya som jag använde i detta arbete. Detta arbete ska visa en smidig teknik att deformera vissa delar av en komplicerad modell och få andra delar att splittras och spridas i en dynamisk simulation som är både fysiskt rätt och ser visuellt bra ut. Resultatet är en kort animationsfilm som visar teknikerna i praktiken. Enskilda användare av 3Dapplikationer exempelvis studenter kommer ha nytta av arbetets olika delmoment och kan hänvisa till informationen.

I denna uppsats beskrivs metoder för att skapa en arm i 3D samt att lägga in den i ett foto där den ersätter en riktigt arm. Anledningen till detta är att kunna skapa effekter i filmer och bilder som inte är möjliga med analog teknik. I denna uppsats kan man läsa om tekniker som används i varje del av utvecklingsprocessen och problem som uppstår samt lösningar och tips. I uppgiften finns det med delar som Modellering, Texturering, Rendering, Kamera Matchmoving och Compositing.

This master's thesis deals with the creation of visual effects in 3D graphics applications. Rendering scenes using rasterization method and OpenGL library is assumed. The theoretical part describes several selected effects and then analyzes the approach used for their implementation. It focuses on the principles of rendering passes. Subsequently, the thesis focuses on the development of a software library which aims to simplify the process of programming effects. The resulting library reduces the time and knowledge required for the creation of effects. Automatic shader code generation is performed. Substantial feature is also the possibility to combine definitions of effects into a single unit.

The simulation of natural phenomena such as clouds, smoke, fire and water is one of the most important research areas in computer graphics. Clouds are an essential component of any outdoor virtual environment, they add an important element of visual detail without which the environment would feel unrealistic. This paper describes an approach for setting up a cloud simulation. Clouds in our system are modeled using cellular automaton. To accelerate the simulation and its visualization, we implement both  entirely on programmable floating-point graphics hardware. The main part of the algorithm is implemented in a fragment shader and therefore takes full advantage of the highly parallel structure. The algorithm can generate result at real-time or near real-time frame rates. We also simulate the interaction of clouds with light, including self-shadowing.

This paper deals with possibilities and functions of modern graphic accelerators and with measuring performance under OpenGL interface. Widespread algorithms to render scene in real-time are used. It focuses on how to test every part of accelerator's graphic pipeline as well as measure performance in rendering of advanced effects and theoretical speed at general purpose calculations through graphic processor. This testing is realized by implementing multiple test series and their further evaluation. Final application enables setting of test parameters and outputs a score, by which is possible to judge accelerator's performance in comparison among themselves.