基于GPU的三维弧面渐变填充技术研究与实现

Design and Implementation of 3D Line Symbol Gradient Fill Based on GPU

在三维标图绘制应用系统中,线面标号的绘制经常使用渐变填充处理,以更直观地表达绘制对象所包含的趋势和程度信息。为解决标绘于三维地球上的光滑弧面对象的渐变填充绘制效率低下的问题,设计并实现了辐射渐变和线性渐变两种不同的渐变填充效果的高效算法;同时通过渐变方向、中心位置和颜色权重等参数来控制渐变效果,以适应实际使用中多样化的显示需求。考虑到固定管线渲染在大量点面数据处理上的劣势,算法使用GPU内部的可编程着色器,在不影响绘制效果的基础上大幅提升了绘制速度。实验结果表明,基于着色器对三维光滑弧面渐变填充,相比于固定管线渲染有着突出的性能优势,能够将运行时间缩短5倍以上,且在数据量较大的情况下也能保证较高的显示帧率。

In 3D plotting application system,the gradient fill of surface has been applied in many occasions to more intuitively expresses the trend and degree information in the drawing object.In order to solve the problem of lowefficiency of gradient filling in smooth surface objects drawn on 3 D earth,we design and realize an efficient algorithm of two different gradient filling effects(radiation gradient and linear gradient).At the same time,by setting the parameters like direction,center position and color weight it controls rendering effect to adapt the diversification of demand in actual use.Considering the lowefficiency of fixed pipeline rendering in processing a large number of data,the algorithm uses a programmable shader inside the GPU to deliver a substantial performance increase while maintaining satisfactory rendering results.Experiments showthat compared with traditional fixed rendering pipeline,shader has achieved outstanding performance advantages,reduction of the elapsed time by more than 80 percent,and ensuring high display frame rate in the case of a large amount of data.