Studies On Implement Technology Of Augmented Reality

Augmented reality (AR) is dedicated to combine virtual objects with the real world. It can provide a more natural user interface for engineers and establish fascinating environment for education and entertainment applications. AR reasearch encompasses a large number of areas in computer science. In order to register virtual objects in the real world with sufficient accuracy, early work is concentrated on the sensor technology and image process technology. With the development tracking technology, the image quality and the rapid development technology have become a new requirment.The topic of this dissertation is a set of algorithms and methods for photorealism rendering in AR environment and AR soft architecture. The aim is to promote the display quality and provide a stable soft framework for AR rapid development. This paper begins with photorealism rendering technology. It modifies two shadow generating method for AR environment, and then provides a real world lighting detection method for marker tracking based AR system. These two technologies are then put into an AR scene graph based framework (ARSGF). ARSGF consists of several components, each of which addresses different functions.The framework that provides support for scene graph manage, photorealism rendering, device abstract and collaboration, gives convenience for rapid AR system development. The contributions of this dissertation are as follows.Fistly, for shadow generation, two improved methods, shadow volum and shadow map, are modified to generate shadows between vitual objects and real objects for different AR applications.Secondly, in consistence illumination, a light detection method is proposed, which builds a detection model based on the relationship between the irradiance of the tracking markers and the real light. This model can generate virtual lights to simulate the real lights gradually in cameral coordinate space. This method can generate virtual light in the environment with one and two real light. Based on this method, a same method generate virtual light in global coordinate space is also presented.Thirdly, in software framework, a scene graph based augmented reality development framework (ARSGF) is proposed. It provides support for rapid AR application development.All works described in this paper are integrated into the ARSGF software framework. Three applications are developed based on ARSGF. They give the particular presentation of how to design and implement AR systems in the ARSGF archietecture.