In recent years several depth cameras have emerged on the consumer market, creating many interesting possibilities forboth professional and recreational usage. One example of such a camera is the Microsoft Kinect sensor originally usedwith the Microsoft Xbox 360 game console. In this master thesis a system is presented that utilizes this device in order to create an as accurate as possible 3D reconstruction of an indoor environment. The major novelty of the presented system is the data structure based on signed distance fields and voxel octrees used to represent the observed environment. / Under de senaste åren har flera olika avståndskameror lanserats på konsumentmarkanden. Detta har skapat många intressanta applikationer både i professionella system samt för underhållningssyfte. Ett exempel på en sådan kamera är Microsoft Kinect som utvecklades för Microsofts spelkonsol Xbox 360. I detta examensarbete presenteras ett system som använder Kinect för att skapa en så exakt rekonstruktion i 3D av en innomhusmiljö som möjligt. Den främsta innovationen i systemet är en datastruktur baserad på signed distance fields (SDF) och octrees, vilket används för att representera den rekonstruerade miljön.

<p>Real-time global illumination has been a very important topic and is widely used in game industry. Previous offline rendering requires a large amount of time to converge and reduce the noise generated in Monte Carlo method. Thus, it cannot be easily adapted in real-time rendering. Using voxels in the field of global illumination has become a popular approach. While a naïve voxel grid occupies huge memory in video card, a data structure called <i>sparse voxel octree</i> is often implemented in order to reduce memory cost of voxels and achieve efficient ray casting performance in an interactive frame rate. </p> <p>However, rendering of voxels can cause block effects due to the nature of voxel. One solution is to increase the resolution of voxel so that one voxel is smaller than a pixel on screen. But this is usually not feasible because higher resolution results in higher memory consumption. Thus, most of the global illumination methods of SVO (sparse voxel octree) only use it in visibility test and radiance storage, rather than render it directly. Previous research has tried to incorporate SVO in ray tracing, radiosity methods and voxel cone tracing, and all achieved real-time frame rates in complex scenes. However, most of them only focus on static scenes and does not consider dynamic updates of SVO and the influence of it on performance.</p> <p>In this thesis, we will discuss the tradeoff of multiple classic real-time global illumination methods and their implementations using SVO. We will also propose an efficient approach to dynamic update SVO in animated scenes. The deliverables will be implemented in CUDA 11.0 and OpenGL.</p>

The subject of this thesis is an implementation of realistic rendering of voxel scenes using a graphics card. This work explains the fundamentals of realistic rendering and voxel representation of visual data. It also presents selected hierarchical structures usable for acceleration and describes the desing of a solution focusing on the representation of voxel data and their rendering. The thesis describes libraries created as part of the project and algorithms. It also evaluates time and memory requirements of the application along with graphical output.

This thesis deals with the global illumination in the scene by using Voxel Cone Tracing method. It is based on the voxelization of a triangle mesh scene. The voxels can be stored to a full regular 3D grid (texture) or to the hierarchic Sparse Voxel Octree for saving of the memory space. This voxel representation is further used for computations of the global indirect illumination in real time within normal triangle mesh scenes for more realistic final image. Values from the voxels are obtained by tracing cones from the pixels which we want to get illumination for.

This thesis focuses on the analysis of the latest techniques for surface and solid binary voxelization of 3D models. It briefly describes current trends in this problematics and identifies a suitable method with an aim to parallelize the given solution on GPUs. It concretely explains the implementation process of the selected algorithm described in the paper Fast Parallel Surface and Solid Voxelization on GPUs , which produces a sparse voxel octree. The results are very close to those of the original authors. A new solution for extracting a smooth isosurface from this structure based on Marching Cubes is presented as well, providing up to 98 % reduction of the traversed cubes in higher resolutions. The resulting implementation is a framework usable for further voxel scene processing.