The Method Research Of Volume Rendering Illumination Algorithm With Mass Data Based On The Characteristics Of Seismic Data

Volume rendering is a visualization technology to realize 3D data field in a perspective way. It was widely used in many fields of research. Illumination techniques can enhance the display effect of volume rendering and improve the dimensional levels of target area. The traditional Phong model is a simplified local illumination model which lack optical effect shadows. Global illumination simulates the real light environment, but the large amount of calculation is not able to meet the needs of practical application. In seismic geophysical field, signals have low SNR and lack clear border. Based on this, this article aims at how to improve the effect of seismic signal data using Illumination of volume rendering. In this thesis, the main contributions are as follows:1. Proposed an Illumination method based on the enhanced seismic horizon features. Geological horizon is one of the important targets in the field of seismic exploration geological. How to highlight horizon information in the volume rendering directly affects the application of volume rendering in that field. Geological horizon is the interface of different strata, from the angle of signals’ analysis, horizon is usually shown as the signal peak of wave(or trough of wave, zero point). Based on this, this thesis presents an Illumination method based on the enhanced seismic horizon features. The basic idea is to set different Illumination parameters for the horizon data to highlight the horizon information which distinguish from other information redundancy, such as sand body and noise. Experiments show that our method can obviously fuzzy redundant information in seismic data and highlight horizon partial data features;2. Realized an application of the directional occlusion illumination algorithm based on the slice system, and applied to the seismic signal data. Because of seismic signal data is low signal-to-noise ratio, and the geological target is lack of obvious dividing line, etc. Traditional method based on gradient can’t get a good visual effect and other methods have the problem of large amount of calculation. According to the characteristics of the seismic signal, this thesis adopted the directional occlusion illumination algorithm based on the slice system. The basic idea is to automatically set occlusion buffer on each slice, and calculate the Angle of the light and view to get the occlusion factor of the subsequent slice, so as to realize partial shadow effect. The algorithm provides real-time illumination rendering with combination to volume rendering and GPU technology. Experimental results show that the drawing effect of our method significantly increased compared to classic algorithm, our method also highlights the horizon and allow users interactive modify the illumination parameters. In addition we allow the rotation of work area and the movement of light source because of the add of the angle factors. The actual rendering of mass seismic data processing is given in the end;3. Design and implementation of 3D visualization software system of the illumination part, complete the illumination system with real-time interactive function. Let users modify the lighting parameters according to their interests. In this system we realize the simulation algorithm in this thesis.As a consequence, we design and apple the illumination algorithm based on seismic data and horizon enhanced data and successfully applied to the seismic data visualization software system. Through the actual test applications, improve the seismic data illumination effects in volume rendering.