Real-time simulation of meadow

We present a simple method to render outdoor grass meadow in real time. The technique employs vertex shaders to simulate the wagging effect of grass blades in wind blowing. In the vertex shader, a flexible structure for controlling the orientation and animation of grass blades is created. The wagging animation only affects the top vertices of a grass object. This technique achieves convincing results in real-time, and can be applied to other outdoor 3D games or simulations.