Game developers today are putting a lot of effort into their games. Consumers are hard to please and demand a game which can provide both fun and visual quality. This is why developers aim to make the most use of what hardware resources are available to them to achieve the best possible quality of the game. It is easy to use too many performance demanding techniques in a game, making the game unplayable. The hard part is to make the game look good without decreasing the performance. This can be done by using techniques in a smart way to make the graphics as smooth and efficient as they can be without compromising the visual quality. One of these techniques is deferred rendering. The latest version of Microsoft’s graphics platform, DirectX 11, comes with several new features. One of these is the Compute shader which is a feature making it easier to execute general computation on the graphics card. Developers do not need to use DirectX 11 cards to be able to use this feature though. Microsoft has made it available on graphic cards made for DirectX 10 as well. There are however a few differences between the two versions. The focus of this report will be to investigate the possible performance differences between these versions on when using deferred rendering. An application was made supporting both shader model 4 and 5 of the compute shader, to be able to investigate this.

A long-standing difficulty with rendering huge distances is depth-fighting; a visual artefact produced when two or more fragments overlap either due to coplanar geometry or insufficient depth precision. This thesis presents two novel methods, Cascaded Deferred Rendering (CDR) and Logarithmic Cascaded Deferred Rendering (LogCDR), as a solution to solve depth-fighting that is due to insufficient depth precision. This thesis also evaluates an existing method, logarithmic depth buffer, comparing it against the standard depth buffer in OpenGL, CDR and LogCDR. The most prominent solution found was logarithmic depth buffer because of performance, no overhead from frustum division and extensive culling, ease of implementation and conveniences such as easier implementation of transparency. / Ett långvarigt problem med att rendera stora scener är depth-fighting; en visuell artefakt som uppstår när två eller flera fragments överlappar, antingen för att det är ligger direkt på varandra eller för att det inte finns nog med precision i djupbuffern. Detta examensarbete presenterar två nya metoder, Cascaded Deferred Rendering (CDR) och Logarithmic Cascaded Deferred Rendering (LogCDR) som en lösning på depth-fighting som framträder när de inte finns nog med precision. Detta examensarbete utvärderar också en redan existerande metod, logaritmisk djupbuffer, och jämför den med standard djupbuffern i OpenGL, CDR samt LogCDR. Den mest lovande metoden funnen var logaritmisk djupbuffer för dess hastighet, lätthet att implementera och enklare att lägga till stöd för transparans till.

Background. In this experiment forward, deferred and tile-based forward rendering techniques are implemented to research about the light-rendering performance of these rendering techniques. Nowadays most games and programs contains a graphical content and this graphical content is done by using different kind of rendering operations. These rendering operations is being developed and optimized by graphic programmers in order to show better performance. Forward rendering is the standard technique that pushes the geometry data through the whole rendering pipeline to build up the final image. Deferred rendering on the other hand is divided into two passes where the first pass rasterizes the geometry data into g-buffers and the second pass, also called lighting pass, uses the data from g-buffers and rasterizes the lightsources to build up the final image. Next rendering technique is tile-based forward rendering, is also divided into two passes. The first pass creates a frustum grid and performs light culling. The second pass rasterizes all the geometry data to the screen as the standard forward rendering technique. Objectives. The objective is to implement three rendering techniques in order to find the optimal technique for light-rendering in different environments. When the implementation process is done, analyze the result from tests to answer the research questions and come to a conclusion. Methods. The problem was answered by using method "Implementation and Experimentation". A render engine with three different rendering techniques was implemented using C++ and OpenGL API. The tests were implemented in the render engine and the duration of each test was five minutes. The data from the tests was used to create diagrams for result evaluation. Results. The results showed that standard forward rendering was stronger than tile based forward rendering and deferred rendering with few lights in the scene.When the light amount became large deferred rendering showed the best light performance results. Tile-based forward rendering wasn’t that strong as expected and the reason can possibly be the implementation method, since different culling procedures were performed on the CPU-side. During the tests of tile-based forward rendering there were 4 tiles used in the frustum grid since this amount showed highest performance compared to other tile-configurations. Conclusions. After all this research a conclusion was formed as following, in environments with limited amount of lightsources the optimal rendering technique was the standard forward rendering. In environments with large amount of lightsources deferred rendering should be used. If tile-based forward rendering is used, then it should be used with 4 tiles in the frustum grid. The hypothesis of this study wasn’t fully confirmed since only the suggestion with limited amount of lights were confirmed, the other parts were disproven. The tile-based forward rendering wasn’t strong enough and the reason for this is possibly that the implementation was on the CPU-side.

Context. Aliasing artifacts are a present problem in both the game industryand the movie industry. With the GCN (Graphics Core Next) architectureused on both new generation of consoles; Xbox One and Playstation 4, aunified Anti-Aliasing solution can be constructed with high performance,temporal stable edges and satisfying visual fidelity. Objective. This thesis aims to implement several prototypes which willbe utilizing GCN architecture to solve aliasing artifacts such as temporalstability. Method. By doing performance measurements, a survey and an experimenton the constructed prototypes and current state of the art solutionsthis thesis will create both a benchmark between given state of the art solutionsfor the industry and at the same time evaluate the new solutions givenin this thesis. Result. With having potential of being the fastest Anti-Aliasing solutionin the field it does not only bring high performance, but also very temporalstable edges and satisfying visual quality. Conclusion. If not used as a standalone solution, the prototype can be decoupledfrom GCN specific features and be a very suitable complement forMulti Sample Anti-Aliasing which can not handle alpha clipped edges.

Spel idag kräver en enorm mängd arbetstimmar för att skapas, därför behövs alltid sätt att spara tid och automatisera processer. Algoritmer för polygoniseringen av skalärfält, som Marching Cubes, har under de senaste åren blivit ett allt vanligare tillvägagångssätt för att automatiskt generera terräng. Scenkomplexiteten och kraven för visuell kvalitet i dagens spel ökar ständigt. Därmed kommer också kravet för prestandaeffektiva renderingsmetoder. Deferred rendering är en renderingsmetod som kan hantera scener med stora mängder ljuskällor och hög scenkomplexitet samtidigt. För att undersöka integreringen mellan procedurellt skapad terräng och en deferred rendering pipeline, skapades en applikation i DirectX 11 för att undersöka implementeringen och potentiella optimeringar av denna integration. / Detta projekt handlar om slumpmässig procedurell skapning av digital terräng för bruk inom datorspel, och hur man i denna kontext kan ta nytta av en grafikmotor som använder renderingstekniken deferred rendering. / Carl Engström can be reached at: Phone: 076-102 86 00 Mail: Lemmibl@gmail.com Felix Nawrin Oxing can be reached at: Mail: felix@nawrin-oxing.se