In defining the effects of 3D structure on seismic energy it is useful to trace ray paths in such structures.  These models can be useful in determining whether there are illumination problems due to the survey geometry and can be used to more evenly illuminate subsurface features by changing the survey geometry, or to determine whether it will be possible to process datasets for particular reflections (especially important in sub-salt imaging).  The following are simple examples from two 3D models:

3D Raytracing of complex models is done using GX Technology's programs - a 2D section from a 3D model is displayed below:

A simple 3D model is shown in projection along the Y- axis below: