可视化系统DVS中图的局部放大功能实现原理解析

The Implementation of Partial Zoom in Data Visualization System

在基于可视化软件包VTK开发的数据可视化系统DVS中,新增图的局部放大功能。采用依据选择区域相对于视区的位置和大小决定相机位置,从而实现局部放大。在界面处理过程中,尝试用实时替换VTK的事件处理函数方法来解决VTK不能处理鼠标移动事件的缺陷,设计实现了橡皮筋选择方式。结果表明在软件开发的过程中灵活地使用外部方法可弥补某些应用软件包的功能不足。

Partial zoom is added as a key function into the Data Visualization System developed basing on VisualToolk-it.It is implemented by deciding the position and the focus position of the camera according to the size of the viewport and the position and the size of the selected area on the graph.Being the limitation in VTK,mouse movement event could not be handled perfectly.It is an interesting experience to implement that with developed message handling method instead of that in VTK during developing the elastic rectangle which is used for deciding the selected area.The result indicates that it may compensate some deficiency in the ToolKit with special methods outside of it.