Block modeling and shooting ray tracing in complex 3-D media

We propose block modeling to suit complex 3-D media. Instead of layers, geological media are regarded as an aggregate of geological blocks, which have their own attributes, such as shape, size, density and seismic wave velocity. The structure of blocky model is Body --> Block --> Interface Point --> Coordinate. We construct interfaces in the model with triangles, which fit most complex media. For normal vectors change abruptly across the linked boundaries, normal vectors of triangles are smoothed to suit ray tracing. We present some methods for shooting ray tracing in 3-D: triangle-subdivision, triangle-division and subtriangle methods. Our calculation indicates that the subtriangle method is most efficient. We present real cases for some complex models and ray tracing results on these models.