Browsing by Subject "vokseli"

The goal of real-time rendering is to produce synthetic and usually photorealistic images from a virtual scene as part of an interactive application. A scene is a set of light sources and polygonal objects. Photorealism requires a realistic simulation of light, but it contains a recursive problem where light rays can bounce between objects countless of times. The objects can contain hundreds of thoudands of polygons, so they cannot be processed recursively in real-time. The subject of this thesis is a voxel-based lighting method, where the polygonal scene is processed into a voxel grid. When calculating the indirect bounces of light, we can process a small amount of voxels instead of the vast amount of polygons. The method was introduced in 2011, but it didn't gain much popularity due to its performance requirements. In this thesis, we studied the performance and image quality of the voxel-based lighting algoritm with a modern, low-cost graphics card. The study was conducted through design research. The artefact is a renderer that produces images with the voxel-based algorithm. The results show that the algorithm is capable of a high frame rate of 60 images per second in a full-hd resolution of 1920x720 pixels. However, the algorithm consumes most of the time spent forming the image, which doesn't leave much time to simulate a game world for example. In addition, the voxelization of the scene is a slow operation, which would require some application-specific optimizations to be performed every frame in order to support dynamically moving objects. The image quality improves greatly when compared to a scene that doesn't calculate indirect light bounces, but there is a problem of light bleeding through solid objects.