Ray Casting Algorithm And Drill Core From Three-dimensional Visualization

Visualization in scientific computing and drilling data3D visualization are applied more and more widely in geological exploration, is an important technical method to realize the core functions of the mine ore body drilling integrated visualization. Provide guidance and help to the planning of mining, mining, engineering facilities management and other aspects, has a very important practical value. However, the complexity and diversity of geological environment, ore body data is usually bigger, which increases the difficulty of the geological staff analysis of the geological environment, limiting the practical application of these technologies. Therefore, the proper classification management of drilling data and improved volume rendering algorithm to speed up rendering is very important. In this paper, National major scientific instrument and equipment development project subtask "core data stereo mapping display software research and development" is applied by Nanjing Institute of Geology and Mineral Resources as the engineering project application background, discusses the method and process of the mine ore body drilling integrated visualization, and mainly has the following tasks:1. Studied the rendering algorithm of3D volume data. Mainly introduces the basic principles, algorithm process and image synthesis of ray casting algorithm. Then three classical volumes rendering algorithm:the Footprint method, Shear-warp and3D texture method to analyze the advantages and disadvantages of algorithm. And the rendering performance comparison, the experiments show that in the four kinds of volume rendering algorithm, ray casting algorithm produces the highest image quality.2. For the ray casting algorithm render the ore body data is very slow, not up to the requirement of real-time rendering. This paper presents an accelerated ray casting algorithm based on CUDA, using the parallel architecture hardware CUDA, CPU and GPU work together to realize the parallel execution of the function. Serial processing program executed in the CPU side, the execution of complex parallel light sampling computing at GPU. The use of bounding box technology and ray leaping algorithm can reduce the number of projected light and sampling point. Finally, the accelerated algorithm implementation process is presented, and the experimental results show that the accelerated algorithm can not reduce the image quality at the same time, improve the rendering speed, can achieve close to real-time rendering.3. The drilling core3D visualization. This paper introduces the basic concept of drilling data. The drilling data are classified according to the type of application, and the object-oriented method is used to manage drilling data. This paper provides a linear model and cylinder model for three-dimensional display of core drilling column, at the same time using hyper spectral data and core images obtained from the core scan for auxiliary displaying, in order to achieve a true reflection of core drilling column, convenient review and analysis for geological staff.4. The display of terrain3D visualization. Introduced digital terrain representation of terrain3D model, and then focuses on the analysis of the two main classification methods of digital elevation model in terrain modeling:the regular square grid model (RSG) and the triangulated irregular network model (TIN), and both advantages and disadvantages of modeling methods are analyzed. Finally, this paper proposes insertion point by point method to build triangulated irregular network to generate the3D visualization of terrain, and use texture mapping technology to display realistic topography. Experimental results show that this method can display3D terrain well.