基于几何与图像混合绘制中的快速WARP变换算法研究

基于几何与图像的混合绘制中，3D Warp算法以严格的数学变换为基础，从而能够保证准确的投影关系，但该算法在实时绘制阶段需进行大量的数学运算，故其时间复杂度较高，该文提出了一种新的快速Warp变换算法，算法以3D Warp算法为基础，采用了崭新的投影过程，从而使时间复杂度较3D Warp算法有较大幅度的下降（降低约7．51倍）。同时，该算法是一种流水结构，能够有效利用现有的加速硬件，而无需改变图形硬件的体系结构。

A Fast 3D Image Warping Algorithm For Hybrid Rendering

A new hybrid approach to render highly complex geometry model is presented in this paper. This approach, which is based on our fast 3D image warping algorithm, has two components. The first component is an adaptive image modeling method for geometry model. According to this method, a complex geometry model will be replaced by some images, which can represent the original geometry model very well. Especially, this method can fill the holes in one image correctly and effectively. The amount of images to represent geometry model can be adjusted adaptively according to a given accuracy. This method is convenient and effective, because it changes traditional modeling and rendering procedure, and takes advantage of image based rendering(IBR) to render geometry model. The second component is a fast 3D image warping algorithm, which can warp the images with depth very quickly. Unlike the traditional 3D image warping algorithm, this algorithm spends less time fulfilling image warping and can take advantage of texture mapping hardware effectively. This algorithm changes the traditional image warping procedure. Firstly, when viewpoint changes, all the pixels in original image will be shifted to new positions in the same image according to prospective. This procedure is fast and convenient, because both the original and new positions of the pixels are in the same image, and it is a simply parallel shift for every single pixel. We call this procedure 3D point warping. Secondly, the image with shifted pixels will be regarded as a texture image. The algorithm uses texture mapping hardware to derive result image. We call this procedure 3D plane warping. We present results that demonstrate our approach's ability to fulfill fast image modeling and rendering for highly complex geometry model.