Research On Volumetric Model-based Three-dimensional Visualization Of Ocean Water

With the continuous development and advancement of computer graphics, theapplication domain for three-dimensional geographic information system is no longerconfined to simulation of fine3D environment. Simulating complex three-dimensionaldynamic water environment is also increasingly in-depth. When we are simulating the waterin3D spatial data, it is the most important that how to express water in3D spatial data field.At present, the visualization of3D data is a core study in computer visualization. Because thesea water has its rich resources and is wide, people pay more attention to the study of theexpression of three dimensional space environment of ocean water. In the study ofenvironment visualization with ocean water, people would like to focus on the expression ofocean wave model. In other words, rendering virtual water surface of the ocean is theexpression of ocean water. However, it is not with the internal information of ocean water.When we take advantage of volume rendering techniques, it is more effective to retain theinternal properties about ocean water. It does not affect rendering the surface of the oceanwater, but it is more difficult to rendering it. Therefore, it is necessary to study on volumetricmodel-based three-dimensional visualization of ocean water.In this paper, research goal is implementation of3D visualization of sea water. Thispaper includes three main points: firstly, there is the analysis and selection of voxel model;secendly, that is the selection and application of light model; lastly, it is the size of renderingocean water which includs small area rules voxel rendering and large area of non-uniformvoxel rendering. In this paper, we use two volume rendering methods to express the oceanwater, which are splatting algorithm and GPU-based ray-casting algorithm. On one hand, werender small ocean water with sea water molecules and aerosols using voxel unit with regulargrid based on the splatting volume rendering. At the same time, we utilize two kinds oflighting model to express the feature of voxel collection. Its observation is real-timeasymptotically type, and it can create a strong visual impact. On another hand, we renderocean water using voxel with regular grid based on GPU-based ray-casting volume rendering.Those voxel sets are chaotic. Although it is more efficient to draw a large sea area, it is thelack of the characteristics of incremental observation. The key technology of the experimentproves that using voxel rendering of ocean water is feasible.Not only that, it also improvesdynamic surface rendering of the ocean water. Outstanding achievements of renderingdynamic surface of the ocean water in the spherical coordinate system are integrated intovolumetric visualization the ocean water. It is more realistic and more vivid to simulate real3D environment. Following, making use of3D development platform, which includes OSGand osgEarth, is to complete simulation experiment related with ocean water environment visualization based on the above research foundation. That means that expression method ofocean water in3D environment is technically feasible. It provides a solid technical support forsimulating marine3D spatial date field, such as scalar field and vector field.