Real-time Global Illumination Based Graphic Rendering Engine Research And Application

With the development of the fields, such as visual world,3D imitation,3D movie and 3D game, more and more people focus on how to quickly generate bright and colorful 3D graphics effects. It leads to a lot of 3D rendering engines appearing like the bamboo shoots after a spring rain. The computer graphic level of foreign countries is generally higher than domestic. To meet the domestic needs of 3D application, the research of 3D rendering technique has become a meaningful thing. The main content of this paper is the research of global illumination based 3D rendering engine, it is divided into three parts.Firstly, we designed and implemented a framework of 3D rendering engine which contains resource manager, scene manager, scene editor and scene rendering. The resource manager is mainly responsible for the imported resource file such as model, material, texture and so on. The scene manager is mainly responsible for the management of model instances in the scene. The scene editor is mainly responsible for updating the property of various elements in the scene. The scene rendering is the core module which is responsible for rendering all the model instances and graphic effects in the scene. In this paper, we call the interface of graphic card through OpenGL/GLSL programing language to implement the rendering pipeline. Furthermore, we implement some 3D graphic functions and effects under our HarryGE engine framework, includes model, material and texture importing, skeleton animation rendering, random terrain generation, skybox, smoke and particle system, text and sound, multi-camera roaming and global illumination.Secondly, the paper proposed the rasterization based ray-scene intersection algorithm which use a coarse uniform grid and three high resolution layer depth image to represent the scene. Moreover, the improved ray-scene intersection method is applied to a new ray tracing framework which supports all kinds of global illumination algorithm, such as Ray casting, Whitted ray tracing (including shadow, reflection and refraction), Ambient occlusion, Soft shadow and Path tracing. The experimental results show that our method achieved high quality of efficiency and accuracy.Finally, to verify the practicability of our 3D rendering engine, we apply it to the simulation of crowd evacuation. In our paper, we improved the RVO based crowd evacuation algorithm which contains local collision avoidance (RVO based) and global path planning (Kd-Tree and SPFA based). We firstly initialize the location of obstacles and agents model instances in the scene, then update the property of agent models instances in dynamically computed data until the process over.In conclusion, our paper proposed a global illumination based 3D rendering engine. To demonstrate the practicability, it is applied to some 3D applications, including the simulation of crowd evacuation.