3维城市景观阴影绘制算法的研究与实现

Research and Implement of Shadow Rendering Algorithm in 3D City Scene

真实感3维可视化技术是数字城市的关键技术之一,随着CPU和GPU能力的不断增强,使得实时的真实感阴影得到广泛的应用。在3维城市景观中,通过多边形模拟建筑物,利用阴影数学的原理,在建筑物渲染过程中利用变换矩阵来生成阴影,并通过多边形偏移和模板测试来改善阴影效果;通过BillBoard技术构建树木,采用光影贴图的方法来生成阴影。实验证明该算法计算简单、速度快,能够满足3维场景真实性与实时性的要求。

Realistic 3D visual technology plays a key role in digital city and the real-time realistic shadow is widely applied as the CPU and GPU is enhanced. In 3D city scene, the structures are simulated by the polygons and the shadow is generated by the transform matrix and improved by the polygon offset and stencil buffer testing; the trees are created by the Billboard technique and the shadow is generated by the shadow map in the paper. At the end of the paper, the method with experimental data is tested and the method shows that the algorithm is simple, quick, and satisfied with the authenticity and real-time demand in 3D scene.