AN EVALUATION OF REAL-TIME GLOBAL ILLUMINATION TECHNIQUES

Abstract: Real-time global illumination techniques are becoming more and more realistic as the years pass and new technologies are developed. ‘This report therefore set out to evaluate di‚fferent implementations of real-time global illumination.‘ The three implementations that are looked at are Unity, Unreal and a Voxel Cone Tracer. For Unity and Unreal we also look at their three main sett‹ings for global illumination, in order to look at the diff‚erences between methods using pre-computation and those that are run-time focused.Th‘e evaluation focuses on visual quality and render times. In order to compare render times we look at how the framerate is e‚ffected by both scaling up the number of lights and then adding motion to the light sources. When comparing the results from a visual quality perspective we made use of the perceptual quality metrices SSIM and HDR-VDP-2 with reference images rendered in Blender. For these tests we use three di‚fferent scenes with di‚fferent lighting conditions.We conclude that while the Voxel Cone Tracer faced large framerate problems when lighting was scaled up, the higher end implementations in the form of Unity and Unreal, neither had any problem keeping a high frame rate when the same tests were applied to them. Th‘e visual quality tests faced some problems as the tests using HDR-VDP-2 had problems ge‹ing any good results. Th‘e results from SSIM were more useful, showing that there still is progress to be made for all the implementations and that the ones using more pre-computations generally perform be‹tter.