| Popis: |
We propose an improved block modeling technique to describe complex 3-D media. A geological medium is represented as an aggregate of geological blocks rather than layers, which have their own attributes such as shape, size, density and seismic wave velocity. The structure of a blocky model is Body → Block → Interface → Point. We construct interfaces in the model with triangles, which fit most complex media. For normal vectors change abruptly across the linked boundaries, normal vectors to the interfaces are everywhere smoothed by an approximate estimation and thus approximately C2 continuous to generate relatively accurate 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. |
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