分形布朗运动 FBM（Fractional Brownian Motion）能真实地表现自然场景，但计算量大，运行费时，在实际的应用中对硬件的要求比较高，难以满足虚拟场景实时生成需求。三角形边界细分法能很好地满足场景实时交互的要求，但在细节描述方面不如FBM。提出一种把两者结合起来生成地形的有效算法，在 FBM的基础上对各边法线进行统一方向扰动，通过比较中心点与阈值关系来控制迭代次数，最后采用滤波技术解决运动时产生的闪烁问题。实验证明该算法既能充分表现地形表面的丰富细节，又具有速度快、方便快捷的特点。%Fractal Brownian motion (FBM)can truly represent the natural scenes but is computation-intensive and time-consuming.In practical applications,it has strict demands on hardware and is difficult to meet the requirement of real-time visual scene generation. Triangular boundary subdivision can well satisfy the demand in real-time interaction of scenes but its detail description is not as good as FBM’s.We propose an effective algorithm to generate the terrain through the combination of these two.It perturbs the normals at each side with unified direction based on FBM,and controls iteration times by comparing the relationship between the centre point and the threshold,fi-nally it adopts filtering technique to solve the flashing during the motion.Experiment proves that the algorithm fully reflects the rich details of the terrain surfaces and also has the features of fast speed and convenience.
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