| With the development of science and information technology,computer technology,network technology and other modern science technology have been widely used in all walks of life.Of course,these technologies are also applied in the field of education,which is called Computer-Based Education(CBE).The Outline of the National Plan for Medium-and Long-term Education Reform and Development(2010-2020)states that one of the tasks of "accelerating the process of educational informatization" is to "strengthen the developing and applying of high-quality educational resources".Digital educational resources,as an important part of Computer-Based Education,are not only a significant offspring in the development process of educational informatization in China,but also a vital embodiment of the development stage.Digital educational resources have brought many benefits to educatioa For example,in the teaching process,part of teaching contents can be visualized by computer to guide the teaching and learning.Especially for the abstract and diffcult subject contents,with the help of computer technology to visualize,make them easier for teachers and students to understand and apply.For instance,there are many abstract concepts that are difficult to understand for physics teaching in junior and senior high school,which are difficult to be explained by language alone.Therefore,teachers are confronted with tough challenges.For example,the electric potential field is invisible,but it is a real physical phenomenon.This part of the learning content is abstract and theoretical,which requires students to have a strong spatial imagination and logical thinking ability.So it is generally difficult for students to learn.Traditionally,demonstrative contents of electric potential field are mostly drawn in qualitative way,which has the problem of large error.And the different textbooks adopt different drawing method.With computer technologies applying in various subjects,some scholars put forward using the computer technology to achieve electric field visualization,and to provide intuitive and scientific learning materials for education.Based on the previous research,we focus on the numerical field rendering technology,and propose a new numerical field rendering method.The main contents of our research include:modeling,visualization and field point optimization.The related work of this paper is as follows:(1)In this paper,the numerical field is modeled by implicit function This step is the most basic work for drawing the numerical field.(2)Based on the mathematical model of numerical field,the visualization of numerical field can be realized.The visualization of numerical field is mainly divided into two steps:how to obtain field points and how to connect field points to get field lines.The discrete field points is the fundamental of numerical field rendering.In this paper,the algorithm of two-dimensional MC(Marching Cubes)is used for reference to obtain planar field points.For the discrete field points,if they are simply connected with each other through line segments.Then we will get a series of broken line graphs,whose accuracy and smoothness are difficult to meet the requirements.In this paper,we compare and study the existing curve smoothing algorithms and finally decide to use Hermite interpolation algorithm to connect the points.(3)On the basis of realizing the numerical field rendering,we also optimize the compression processing of field points.It can promise the field lines with fewer "key"field points to guarantee the smoothness and accuracy of field lines.In this way,the data storage space of field points can be reduced and the drawing speed of field lines can be accelerated.On the foundation of the theoretical study of the above algorithm,we implement the algorithm in the certain hardware and software environment and plot the numerical field of point charge(potential field)in electrostatic field.The experimental results show that the line is smooth and accurate. |
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