Abstract: Mixed wave is real-time rendered in the visual system of maritime simulator. Inverse fast
Fourier transform (IFFT) Gerstner wave model is used to compute the motion of ocean wave. Six
parameter spectrum, a frequency spectrum showing energy distribution of mixed wave, is applied to
construct the wave number spectrum of mixed wave. The wave number spectrum is contained by the
Fourier coefficients of height field and choppy wave. By IFFT, the position of mixed wave surface is
gotten. Further, mixed wave is rendered. The rendered mixed wave is affected by the low frequency
wave with long wave length. Its shape is smooth and flat, differs from that of wind wave, but is
similar with the actual ocean wave. The presented method of mixed wave rendering is used in the
visual system of the maritime simulator, and the frame rate meets the request of real-time rendering.

Key words: ocean wave rendering, mixed wave, wind wave, wave number spectrum, six parameter
spectrum