Computer generated animation can be used very effectively as a tool in accident reconstruction. It is especially effective in conveying the results of engineering analysis to a non-technical audience. This has been found particularly useful when describing dynamic events. This paper emphasizes methods for accurately portraying geometric data and object trajectories. Techniques will be explained in the context of an example accident reconstruction animation.Discussed, in particular, are the methods of having a computer-generated vehicle follow three-dimensional terrain, of accurately aligning photographic data with terrain data, and of accurately creating contour and profile lines.Also discussed are techniques for demonstrating both the methods used and the accuracy of the animated scenes.