Includes bibliographical references (p. 51-57).

One of the main goals of computer graphics is the fast synthesis of photorealistic image of virtual 3D scenes. The work presented in this thesis addresses this goal of speed and realism. In real-time realistic rendering, we encounter certain problems that are difficult to solve in the traditional 3-dimensional geometric space. We show that using an image-space approach can provide effective solutions to these problems. Unlike geometric space algorithms that operate on 3D primitives such as points, edges, and polygons, image-space algorithms operate on 2D snapshot images of the 3D geometric data. Operating in image-space effectively decouples the geometric complexity of the 3D data from the run-time of the rendering algorithm. Other important advantages of image-space algorithms include ease of implementation on modern graphics hardware, and fast computation of approximate solutions to certain lighting calculations. We have applied the image-space approach and developed algorithms for three prominent problems in real-time realistic rendering, namely, representing and lighting large 3D scenes in the context of grass rendering, rendering caustics, which is a complex indirect illumination effect, and subsurface scattering for rendering of translucent objects.

<div>Over the years, the performance demand for graphics applications has been steadily increasing. While upgrading the hardware is one direct solution, the emergence of the new low-level and low-overhead graphics APIs like Vulkan also exposed the possibility of improving rendering performance from the bottom of software implementation.</div><div><br></div><div>Most of the recent years’ middle- to high-end personal computers are equipped with both integrated and discrete GPUs. However, with previous graphics APIs, it is hard to put these two heterogeneous GPUs to work concurrently in the same application without tailored driver support.</div><div><br></div><div>This thesis provides an exploration into the utilization of such heterogeneous GPUs in real-time rendering with the help of Vulkan API. This paper first demonstrates the design and implementation details for the proposed heterogeneous GPUs working model. After that, the paper presents the test of two workload offloading strategies: offloading screen space output workload to the integrated GPU and offloading asynchronous computation workload to the integrated GPU.</div><div><br></div>While this study failed to obtain performance improvement through offloading screen space output workload, it is successful in validating that offloading asynchronous computation workload from the discrete GPU to the integrated GPU can improve the overall system performance. This study proves that it is possible to make use of the integrated and discrete GPUs concurrently in the same application with the help of Vulkan. And offloading asynchronous computation workload from the discrete GPU to the integrated GPU can provide up to 3-4% performance improvement with combinations like UHD Graphics 630 + RTX 2070 Max-Q and HD Graphics 630 + GTX 1050.

Fluorescence is a common effect in nature, it re-emits light by absorbing photons, caus- ing a wavelength shift from a shorter wavelength to a longer one. In recent years, there is an increased interest in including fluorescence in physically-based rendering. Fluorescence behavior is properly represented as a re-radiation matrix: for a given input wavelength, this matrix indicates how much energy is re-emitted at all other wavelengths. However, such a 2D representation has a significant memory footprint, especially when a scene con- tains a high number of fluorescent objects or fluorescent textures. This thesis proposes using Gaussian Mixture Domain to model re-radiation, which allows us to significantly reduce the memory footprint. Instead of storing the full matrix, we work with a set of Gaussian parameters that also allow direct importance sampling. When accuracy is a concern, one can still use the re-radiation matrix data and just benefit from impor- tance sampling provided by the Gaussian Mixture. Our method is useful when numerous fluorescent materials are present in a scene, particularly for textures with fluorescent components. 1

Graphics Processing Units (GPUs) are commonly used to accelerate massively parallel workloads across a wide range of applications from machine learning to cryptocurrency mining. The original application for GPUs, however, was to accelerate graphics rendering which remains popular today through video gaming and video rendering. While GPUs began as fixed function hardware with minimal programmability, modern GPUs have adopted a design with many programmable cores and supporting fixed function hardware for rasterization, texture sampling, and render output tasks. This balance enables GPUs to be used for general purpose computing and still remain adept at graphics rendering. Previous work at the Georgia Institute of Technology has been done to implement a general purpose GPU (GPGPU) in the open source RISC-V ISA. The implementation features many programmable cores and texture sampling support. However, creating a truly modern GPU based on the RISC-V ISA requires the addition of fixed function hardware units for rasterization and render output tasks in order to meet the demands of current graphics APIs such as OpenGL or Vulkan. This thesis discusses the work done by students at the Georgia Institute of Technology and California Polytechnic State University SLO to accelerate graphics rendering on RISC-V GPUs including the specific contributions made to implement and connect fixed function graphics hardware for the render output unit (ROP) to the programmable cores in a RISC-V GPU. This thesis also explores the performance and area cost of different hardware configurations within the implemented GPU.

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.