Improved VolumeLIC Rendering Technology of 3D Vector Field Based on GPU Acceleration

Texture rendering technology can meticulously and vividly visualize characteristic information of 2D vector field such as speed, direction and data correlation by texture lines and color variations. But when extended to 3D flow field, it can’t help researchers to find and analyze the inherent attributes of flow filed characteristics as the problem of occlusion and confusion existed between texture slices caused by spatial characteristic of 3D vector field. To solve this problem, a new sparse noise based improved Volume LIC rendering technology of 3D vector field implemented by GPU acceleration is proposed in this paper. Noise generation followed by Poisson-disk distribution can help noise points to avoid shading each other. To decrease regular patterns and undesired artifacts in the final sparse noise texture, cube-filling Hilbert curve is adopted to traverse the points. And Gaussian filter kernel is adopted to filter out the high frequency region and generate sparse Gaussian noise. The overall algorithm is implemented by GPU hardware acceleration mechanism, GPU based vertex color linear interpolation function and fragment calculation method are used in nose texture sampling step to accelerate the process of LIC texture generation. Finally the LIC noise texture and flow field data are introduced into GPU, GPU based ray casting algorithm is adopted to visualize LIC texture. In the period of ray casting, early-ray termination and empty-space skipping are utilized to effectively improve the rendering efficiency. Meanwhile a variety of effective interactive analysis methods are introduced to check the internal flow field characteristics. Experimental results show that the 3D texture image generated by our method is distinct and delicate, our method can improve the rendering speed, effectively alleviate the problem of occlusion and confusion occurred by too much convolution data in the 3D complex flow field and has nicer effect.