| Interaction, imagination and immersion are three basic characteristics of virtual reality technology. Immersion largely affects the user's virtual experience, the degree of realization of this feature is an important indicator of the quality of the virtual reality system. Virtual environment is a core research area, which affects the immersion feature greatly.Light and shadow effects are the most common dynamic scenes in real life, which impact the implementation degree of the virtual environment greatly. However, because of the real-time and non-material characteristics, the light and shadow effects can only be achieved using dynamic modeling technology in virtual environment. This is the main work of this paper.In the paper, OpenGL is used to complete kinds of light and shadow effects including reflection, highlight, sphere refraction and shadow.In the paper, the workflow of the OpenGL and the features of OpenGL are analyzed first. The features include geometric transformations, the light model and the test technology. These are the base of modeling after.Then, the appearance and physical properties of light and shadow effects are analyzed deeply. On this basis, the algorithms and programming of completing kinds of effects are accomplished. The implementation of the reflection needs to use the matrix transformations, template test and blend of OpenGL. To achieve the highlight effect, the functions about light of OpenGL are main tools. The copy texture and automatic texture reflect of OpenGL are used to complete refraction effects. Then, two algorithms including plane projection and shadow volume are adopted to create the dynamic shadow.Finally, using MFC windows development tools as the OpenGL rendering window environment, a comprehensive virtual environment system is completed to demonstrate the various effects of lighting and shadow. The module of importing the static model, the sky dome, the operator and the model selection are imported into the system to make the system more perfect. |
