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近来,我们在研究三维动态射线追踪和速度反演问题时,用称作“组块模型”(solid modeling)的技术发展了一新型三维模型生成系统。术语“组块模型”指的是,由逻辑系统控制模型内的几何形态,并把要作的模型看作在三维空间中的“组块”或“体元”(“Volumes”)的组合。这些体元中的每一个,其物理参数(如地震波速度、密度)连续变化。不连续变化仅发生在分隔体元的界面处。模型是这样构成的:首先,根据给定的界面组成一些“简单的体元”,接着,把这些简单的体元组合成更为复杂、代表了模型实际情况的立体.通过对体元进行加、减或较复杂的运算(这些都只是布尔表达式的简单运用),就可以很方便地改变模型。每当一模型被确定(或改变),内部逻辑会自动地对三维模型空间的物理一致性(无体元的重迭,无空洞)进行检查。通过纳入各种类型的坐标变换,盐丘和垂直或近垂直的断层等不同形式的复杂构造都能得到应用.
Recently, we developed a new type of 3D model generation system using a technique called “solid modeling” while studying 3D dynamic ray tracing and velocity inversion. The term “chunk model” refers to the logic system controlling the geometry within a model and treating the model to be made as a combination of “chunks” or “Volumes” in three-dimensional space. Each of these voxels continuously varies in its physical parameters (eg, seismic velocity, density). Discontinuous changes occur only at the interface of the separator elements. The model is constructed as follows: Firstly, some “simple voxels” are composed according to a given interface, and then the simple voxels are combined into a more complex cube that represents the actual situation of the model. , Subtraction or more complex operations (these are just simple Boolean expressions), you can easily change the model. Whenever a model is identified (or changed), the internal logic automatically checks the physical coherence (no voxel overlap, voidlessness) in the 3D model space. By incorporating various types of coordinate transformations, various forms of complex structures such as salt domes and vertical or near vertical faults can be applied.