I den här rapporten så visas hur realtidsrendering av fågelfjäder kan implementaras. Ett lindenmayersystem (L-system) används för att skapa geometri med hjälp av ett fåtal bézierkurvor. Naturliga variationer hos fjädrar modelleras genom att introducera externa krafter som ackumuleras slumpmässigt när L-systemet genererar geometrin. Bidirectional texture functions (BTF) används för färgsättning och effektiv modellering av fjäderns finstruktur. BTF är en sexdimensionell struktur som kan representera verkliga material genom att innehålla, förutom de två vanliga texturkoordinaterna, koordinater för betraktnings- och belysningsvinklar. För att kunna använda BTF-texturer på grafikhårdvara så kompakteras dess representation så att den ryms i en tredimensionell textur. Anpassningar görs också för att stödja texturfiltrering och mip-mappning. För att ta fram informationen som BTF-texturen innehåller så modelleras finstrukturen i ett externt animationsverktyg, där ljuskälla och kamera animeras över de samplingspunkter som definierats. Strålföljning används sedan för att generera hur materialet ser ut vid dessa olika vinklar.

The development of Graphics Hardware Technology is blazing fast, with new and more improved models, that out spec the previous generations with leaps and bounds, before one has the time to digest the potential of the previous generations computing power. With the progression of this technology the computer games industry has always been quick to adapt this new power and all the features that emerge as the graphic card industry learn what the customers need from their products. The current generations of games use extraordinary visual effects to heighten the immersion into the games, all of which is thanks to the constant progress of the graphics hardware, which would have been an impossibility just a couple of years ago. Ray tracing has been used for years in the movie industry for creation of stunning special effects and whole movies completely made in 3D. This technique for giving realistic imagery has always been for usage exclusively for non-interactive entertainment, since this way of rendering an image is extremely expensive when it comes to computations. To generate one single image with Ray Tracing you might need several hundred millions of calculations, which so far haven’t been proven to work in real-time situations, such as for games. However, due to the continuous increase of processing power in Graphical Processing Units, GPUs, the limits of what can, and cannot, be done in real-time is constantly shifting further and further into the realm of possibility. So this thesis focuses upon finding out just how close we are to getting ray tracing into the realm of real-time games. Two tests were performed to find out the potential a current (2009) high-end computer system has when it comes to handling a raster - ray tracing hybrid implementation. The first test is to see how well a modern GPU handles rendering of a very simple scene with phong shading and ray traced shadows without any optimizations. And the second test is with the same scenario, but this time done with a basic optimization; this last test is to illustrate the impact that possible optimizations have on ray tracers. These tests were later compared to Intel’s results with ray tracing Enemy Territory: Quake Wars.

When developing applications in Direct3D today, developers can choose between using the fixed function pipeline and the programmable pipeline. The programmable pipeline is more flexible than the fixed function pipeline, but what is the price for high flexibility? Is high flexibility desired at any cost? How is the choice of pipeline affecting performance? The purpose of this master thesis is to evaluate the performance of the two pipelines. This will be achieved by developing a benchmark program, which measures performance when various graphical effects are tested. The results of the evaluation will hopefully help developers to decide which pipeline to use, in terms of performance. In the end we will see that the fixed function pipeline is faster than the programmable pipeline in all our tests.

This essay serves to illustrate the main practical differences between the popular medium-level programming language C++ (C Plus Plus), and the newer high-level language C# (C Sharp). It will focus on the aspects that are readily apparent to the application programmer, such as differing syntax, constraints and capabilities. It will also feature a similar comparison between the open source OpenGL graphics library, and the proprietary Direct3D graphics library owned by Microsoft Corporation. It will not go into the differences in ”under the hood” mechanics that the application programmer seldom have to consider after having chosen his programming language or graphics API, such as C# being compiled into an intermediate language and is run on a virtual machine where C++ is compiled directly to machine code, or the differing principles of rendering in OpenGL and Direct3D. This is by no means comprehensive, many things have been left out or overlooked.

This thesis deals with the detection of Uniform Marker Fields and the position of a camera in a space. The steps of the UMF detection, the Windows Phone 8 platform, DirectX working and the concept of augmented reality are described in the thesis. Implementation and design of the demo application together with the whole architecture of the project is described in the thesis. The result of the thesis is an application using the UMF detector and plotting a 3D object into a scene. Finally the application is tested and evaluated.

This work discusses shadowing methods, analyses them and describes implementation in DirectX 11 API. Theoretical part describes historical evolution of shadow usage in 3D applications and also analyzes shadowing algorithms. This work compares 2 variants of shadow mapping algorithm for omnidirectional lights, based on cube mapping and paraboloid projection, on demo application using quality, performance and implementation aspects.

It is a great challenge to develop a computer game. Today many games are developed in large game studios where lots of skilled people are working together. Everyone has to know what the final game should look like. Game designers are responsible for how the game should feel and look like. This also means that they decide if a programmer has to develop new techniques or not. Sometimes the game designers require lots of new techniques to be developed. Such a new technique may be rendering particle systems with a lot of particles in it. This is where this report will focus. To render particle systems it is necessary to know about the limitations there are in both hardware and software. Until today particle systems have been updated and calculated using the Central Processing Unit of the computer. With Microsoft Direct3D 10 there are new ways to render particles using Geometry Shaders. Geometry Shaders runs on the graphics card. This thesis focuses on testing rendering performance between using Geometry Shaders and not using Geometry Shaders. A questionnaire was sent to Swedish game developers to get more information about relevant topics for investigation. A general answer was that Geometry Shaders always increase particle rendering performance. This thesis investigates if and when the statement is true or not. The hypothesis was obtained from the answers to the questionnaire. Two test applications were used to investigate if the hypothesis was true or false. One test application has particle calculations on the CPU of the computer. The other test application has particle calculations on the GPU of the graphics card. Six different tests were done and the Geometry Shader approach went out to be the fastest in five of the tests. Since not all tests were faster than the CPU approach the hypothesis is not always true.

The game industry have always looked for rendering techniques that makes the games as good looking and realistic as possible. The common approach is to use triangles built up by vertices and apply many different techniques to make it look as good as possible. When triangles are used to draw objects, there is always edges and those edges often make the objects look less realistic than desired. To reduce these visible edges the amount of triangles for an object have to be increased, but with more triangles more processing power from the graphics cards is needed. Another way to approach rendering is ray tracing which can render an extremely photo realistic image but to the cost of unbearable low performance if you would use it in a realtime application. The reason raytracing is so slow is the massive amount of calculations that needs to be made. In DirectX 11 a few new shaders where announced and one of them were the compute shader, the compute shader allows you to calculate data on the graphics card which is not bound to the pipeline. The compute shader allows you to use the hundreds of cores that the graphic card has and is therefore well suited for a raytracing algorithm. One application is used to see if the hypothesis is correct. A flag is used to define if the application runs on the CPU and the GPU. The same algorithm is used in both versions. Three test where done on each processing unit to confirm the hypothesis. Three more tests where done on the GPU to see how the performance scaled on the GPU depending on the number of rendered objects. The tests proved throughout that the compute shader performs considerably better than the CPU when running our ray tracing algorithm.

This thesis deals with library for recording video in the background of 3D application. A library is designed to work under the Microsoft Windows and Linux operation systems.  It records image and also sound. Image recording is supported in OpenGL, Direct3D9, Direct3D10 and Direct3D11. To reduce video data size, library supports image compression using MJPG codec. Audio is recorded by WaveForm audio, Windows Core Audio or ALSA. Recorded sound is for whole operation system. A library is able to record up to two audio streams to accommodate possible microphone input. It can mix audio data together if needed. Output data are then written into AVI file. It is possible to write own text information as overlay that is rendered as part of application screen output.