Abstract: Real-time global illumination rendering plays a crucial role in fields such as virtual reality, augmented reality, film production, and video games, and is an important area of research in realistic rendering. With the continuous improvement of hardware computing power, new methods have emerged in the field of real-time global illumination rendering. This paper reviews the related work on real-time global illumination rendering without pre-processing and categorizes the methods into three types for analysis and comparison. First, we overview the rendering equation and real-time global illumination rendering methods. Then, we introduce and compare three types of real-time global illumination methods: rasterization, ray tracing, and probe-based methods. Finally, we summarize the research progress in real-time global illumination rendering and point out potential future research directions, including optimizing ray tracing sampling, neural network-assisted ray tracing, and optimizing probe-based ray tracing.