volume-rendering

i' am implementing an algorithm of volume rendering "GPU ray casting single pass". For this, i used a float array of intensity values as 3d textures ( this 3d textures describes a regular 3d grid in spherical coordinates ). Here there are example of array values: 75.839354473071637, 64.083049468866022, 65.253933716444365, 79.992431196592577, 84.411485976957096, 0.0000000000000000, 82.020319431382831, 76.808403454586994, 79.974774618246158, 0.0000000000000000, 91.127273013466336, 84.009956557448433, 90.221356094672814, 87.567422484025627, 71.940263118478072, 0.0000000000000000, 0

I am writing a volume render program that constantly adjusts some plane geometry so it always faces the camera. The plane geometry rotates whenever the camera rotates in order to appear as if it doesn't move--relative to everything else in the scene. (I use the camera's viewing direction as a normal vector to these plane geometries.) Currently I am manually storing a custom rotation vector ('rotations') and applying its affects as follows in the render function: gl2.glRotated(rotations.y, 1.0, 0.0, 0.0); gl2.glRotated(rotations.x, 0.0, 1.0, 0.0); Then later on I get the viewing direction by

I have some volumetric imaging data consisting of values sampled on a regular grid in x,y,z, but with a non-cubic voxel shape (the space between adjacent points in z is greater than in x,y). I would eventually like to be able to interpolate the values on some arbitrary 2D plane that passes through the volume, like this: I'm aware of scipy.ndimage.map_coordinates , but in my case using it is less straightforward because it implicitly assumes that the spacing of the elements in the input array are equal across dimensions. I could first resample my input array according to the smallest voxel

I am learning volume rendering using ray casting algorithm. I have found a good demo and tuturial in here . but the problem is that I have a ATI graphic card instead of nVidia which make me can't using the cg shader in the demo, so I want to change the cg shader to glsl shader. I have gone through the red book (7 edition) of OpenGL, but not familiar with glsl and cg. does anyone can help me change the cg shader in the demo to glsl? or is there any materials to the simplest demo of volume rendering using ray casting (of course in glsl). here is the cg shader of the demo. and it can work on my