Research On The Key Technologies Of Virtual Scenes Ocean Construction And Dynamic Light-shadow Rendering

Along with the sea power strategy put forward, and the rapid development ofvirtual reality technology, more and more marine researchers apply the technology onthe ocean. It changes the way of observing and knowing the ocean，so the field ofmarine virtual reality gradually attracts much attention. In the field,one of the maintasks is to simulate real marine environment to the greatest extent. So constructing arealistic, immersive, interactive virtual scene of the ocean quickly by making use ofexisting marine virtual reality data, is the foundation of further study of Marine virtualsimulation. In order to simulate marine virtual scene, researchers must enhance therealism elements. The lighting effects in the water is a very important part of thefactors. Under the sun, the whole ocean scene shows different lighting effects atdifferent times, such as lighting-shadow effect with the sea surface fluctuations, godrays underwater and so on. The phenomenon is most visible manifestation of light inthe marine field. At present, very few researchers engage in studying light effect onthe sea surface and under the sea at the same time, so the results of this paper hasgreat application value.In order to solve the two problems in the field of virtual reality ocean, the paperdesigns Marine Virtual Scene Builder Tool to rapidly build scene at first. It is basedon the virtual reality and visualization of marine platform——i4Ocean, which isindependently developed by Ocean University of China. The tool can process avariety of the data, such as3D model data, marine effects data and visual data, into aunified format for loading. It also provides interactive editing function. This paperprovides dynamic lighting and shadow rendering method applied to the land and sea.It implements lighting-shadow on the sea surface and underwater god rays rendering.These effects can real-time interactive by using the scene builder tool. The mainresearch contents and results of the paper as follows:1) The design and implementation of Marine Virtual Reality SceneBuilder(VR-Bulider)This paper designs a scene builder tool for marine virtual reality data and visualdata. This tool provides uniform data interactive operation interface，supports the custom data formats of i4Ocean and FBX, preprocesses data; The tool, relied onMVAE rendering engine, provides transformation and special propertieseditional function to build a virtual reality environment. It makes a convenient bridgeamong3D modelers, programmers and users，at the same time it makes contributionto the scene builder of i4Ocean.2) The research and implementation of the lighting-shadow rendering technologyon sea surfaceThe paper puts forward a dynamic lighting and shadow simulation method ofocean scene based on GPU. It makes use of the scene builder to complete theinteraction. In order to render dynamic lighting-shadow effect, the paper applieslighting model, shadow algorithm to moving water with programmable renderingpipeline. Users could see lighting and shadow realistic rendering effects of differentlight source through setting lighting-shadow parameters by VR-Builder at differenttimes. The results make up the drawbacks of lighting technology combined withshadow in marine virtual reality areas.3) The rendering technology research and implementation of underwater godraysAccording to the dynamic characteristics of marine fluid，this paper research oneof the most important optical phenomena underwater, underwater god rays. The firststep is making geometrical models of the light beams, and rendering the geometricalmodels according to the motion law of the water surface; The next step, calculate lightintensity and blend the color in GPU with combining refraction，scattering，changedlight intensity for completing underwater dynamic god rays rendering.Research on the key technologies of virtual scenes ocean construction anddynamic light-shadow rendering, provides interactive scene builder tool for i4Ocean，and implements the sea scene light-shadow rendering and god rays drawing under thesea. The results of the research provide visualization services for marine engineeringconstruction， marine resources development and littoral (lake) and other industries.At the same time, it supports the construction of virtual ocean museum system. Sothese results has irreplaceable application value in the field of Marine culturepropaganda.