动态柔性地物三维模拟理论与方法新探

Preliminary Study on Theory and Methods for 3D Simulation of Dynamic Soft Geo-Objects

针对地学动态柔性物体建模,提出GIS流素与柔性体元(GISFlowElementandSoftVoxel)的概念,作为动态柔性地物的基本模拟单元。当忽略体积时,称为GIS流素(FE);当强调体积时,则称为GIS柔性体元(SV)。GIS流素与柔性体元三维模拟基于计算机图形学中的粒子与元球技术,区别在于GIS流素与柔性体元具有明确的地学意义,并基于地学模型突出反映地学规律。现实世界中,水流、泥沙、雪花、云雾、泥石流、熔岩流、草原等均可用GIS流素进行模拟,而构造运动中岩层的挤压、扭曲变形、生物体、树木随风摆动等可用GIS柔性体元进行模拟。该文以水流与土壤模拟为例,论证该方法的应用前景。

In this paper,the concepts,theory and methods of GIS Flow Element(FE) and GIS Soft Voxel (SV) are proposed,which are particularly used for modeling dynamic soft geo-objects and taken as basic simulation units for soft geo-objects.If the volume is ignored,it is named GIS Flow Element; if the volume is emphasized,it is called GIS Soft Voxel.The approach of GIS FE and GIS SV is based on particle system and metaball technology in Computer Graphics.However,GIS FE and GIS SV have definite geographic meaning.Furthermore,their velocity and direction that change over space and time are obtained from scientific computation of geo-models,not from direct control of physical force objects.Considering existing accuracy of data acquisition,GIS FE and GIS SV are simulated based on pixels of remotely sensed imagery.In the real world,water flow,sediment,snowflakes,cloud,fog,mudflow,lava flow and grassland can be simulated using GIS FEs,while the extrusion and deformation of rock layers,organisms and trees blowing in the wind can be realistically simulated using GIS SVs.Through case study on water flow and soil simulation,it is proved that the method is prospect for broad practical use.