Research And Implementation Of The Terrain Rendering Algorithms On The Buffer Object

The terrain rendering algorithms has strong dependence to the computer hardware, so it is classified for the terrain rendering algorithms on the CPU and the terrain rendering algorithms on the GPU. The terrain rendering algorithms on the CPU is the popular terrain rendering algorithms before the GPU becoming the industry standard; With the development of the computer graphics hardware, the terrain rendering algorithms on the GPU become the popular terrain rendering algorithms, and the most representative is the geomipmapping algorithms which is the main research object of this paper.The development speed of the computer is extremely quick comparing to the other things, so the development speed is not with the year, but it is with the month, the day, the hour even smaller units to measure. So the new character of the computer hardware which appear blow the geomipmapping algorithms can't be use in the geomipmapping algorithms; Meanwhile, there are some problems in the geomipmapping: First, because the CPU is the brain of the architecture of the computer, so the CPU's charge is very height. Such as the process management, the file management, the storage management, the equipment management, etc. It is very necessary to free the CPU from the terrain rendering algorithm so that the CPU can deal with other mission better; Second, Comparing to the GPU, the CPU's speed is very slowly [1], meanwhile the RAM's speed is slower than the SGRAM. So it will bring a bottlenecks of the speed between the RAM and the SGRAM when they transmit the terrain vertex data. To solve these deficiencies, there import the VBO(vertex buffer object), the PBO(pixel buffer object) and the double PBO to the GeoMipMapping algorithms. It increase a buffer between the RAM and The SGRAM by the VBO which is not only solve the bottlenecks of the speed between the RAM and the SGRAM, but also improve the speed of the terrain rendering; It can directly transform the texture data from the texture source to the PBO and then transform the texture data from the PBO to the texture object. It reduce the CPU's utilization rate by importing the PBO; It improves the transmission speed of texture source data by importing the double PBO and it can improve the transmission speed of the texture data also. The result of the experiment show that the terrain rendering algorithm on the buffer object not only have improved the speed of the terrain rendering algorithms, but also reduce the CPU's utilization rate. So the terrain rendering algorithm on the buffer object is feasible.