Re: [PyOpenGL-Users] volume rendering
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From: Andrew W. <and...@al...> - 2008-12-08 16:00:17
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Hey Dirk There was a paper a few years ago that did this for shadow mapping, but I > can't find it right now. The main idea is to think of the pixel/voxel as a > cube that is split into two parts, one inside, one outside (in your case, of > the ROI). When you render a pixel that belongs to the cube, you figure out > where it is in the cube (fractional texcoords should be fine), and use that > to decide whether it's in or out, and act accordingly. So for you you could > save a plane equation that says for example that the area left of the x=.75 > point in your cube is inside the ROI, the rest is outside, and you would get > super-voxel resolution ROIs. You could also go beyond planes to higher-order > Got it, sounds a lot like generating an isosurface using marching cubes or something similar. > I guess the question is how often you need to update the ROI, and how high > the ROI resolution really needs to be. > You've hit the nail on the head, I like the idea of using shaders as it won't require much editing of existing opengl code and would provide the best looking results. Thanks for the help, much appreciated. Andrew |