Study On The 3D Visualization Of Seawater Based On GIS

In recent years,with the continuous development and progress of computer graphics technology,3D geographic information system is no longer limited to the simulation of the intensive land environment.The 3D visualization of seawater environment with complicated ontology structure has become a new research hotspot.At present,the 3D visualization of seawater environment,mainly aims at the sea surface and marine water body element information.The sea surface mainly adopts the sea wave model and virtual reality technology,which can satisfy the need of vision,but have a complex implementation process.The 3D visualization of marine water body element information mainly aims at a single kind of water body information elements,but it cannot achieve seawater body 3D visualization as well as information integration and expression of multiple water body element information.This paper studies the 3D visualization of seawater based on GIS,including sea surface and marine water body.In the aspect of sea surface,study the dynamic 3D visualization of sea surface based on simplified sine function model.In the aspect of marine water body,study the 3D visualization modeling of marine water body based on the volumetric model.The specific research works are as follows:(1)Study the sea surface models based on wavefront geometry,including standard sine function model,Gerstner wave function model and the Perlin noise model.Then,it analyses the modeling methods,characteristics and applicability of each model and simplifies the standard sine function model.Using OpenGL and 3D visualization key technology such as LOD model,implements dynamic 3D visualization of sea surface based on simplified sine function model.Experiments show that,simplified sine function model can satisfy the dynamic realistic requirements within a wide range of sea.(2)Study the regular volumetric models of 3D spatial data model,and analyzes the structural characteristics and applicability of each model.On the basis of the requirements which both can realize 3D visualization of marine water body and provide additional information factors of water body for volumetric model,it researches 3D visual model for marine water and expounds the modeling thought and modeling process based on regular volumetric model.The marine water space partitioned thought is introduced and the modeling approach is designed based on the Needle model and Regular Block model.(3)Study and analyze marine water depth data,marine vertical datum,tidal model,commonly used interpolation method to obtain sea bottom and sea surface elevation data.Kriging interpolation method is used to obtain sea surface DEM and submarine DEM,which provides the basic data for 3D visualization modeling of marine water body.Then,it makes the modeling experiment based on the Needle model and Regular Block model.Experiments show that,the Needle model and Regular Block model can satisfy the demand of marine water body 3D visualization modeling.But,the emphasis on the expression of them is different,the former focuses on the expression of marine water space,the expression of the latter focuses on the factors of water body information.(4)Design and Develop the 3D visualization prototype system for seawater to implement the dynamic 3D visualization of sea surface and seawater base on OpenGL graphics library and ArcGIS Engine.