I'm actually looking for some working code, or pseudocode of an algorithm.
The issue: Quite a few groups over the last 5 or so years have succeed in getting volume rendering working using 2D textures, by stacking slices.
With 2D textures there are 3 stacks, one for each major axis.
(Ignore 3D textures for now, there are good reasons for wanting this working with 2D textures).
However, most of them seem to rely on a method of making a stack of _viewpoint_-aligned slices, which slice arbirarily through the (selected to be most perpendicular to the view direction) object-aligned stack.
This results in a series of polygon strips onto which various schemes can be employed to project corresponding texture strips from the object-aligned slices.
eg: Interactive Volume Rendering On PC Hardware (PDF)
Whilst I can understand the basics of what is going on here - cutting bounding polygons with respect to an arbirary plane, ceating an intersection polygon, mapping vertices back to corresponding texture coordinates, etc - trying to wrap my head around the algorithms required isn't getting me very far.
Searching for pseudocode or working code on the web hasn't yielded anything either - either they are all hiding their code or its all been taken down.
At the moment I haven't psyched myself up for the big dive into doing this from scratch, and instead I'm just looking at lowest-cost ways the stack can be kept object-aligned (getting somewhere actually, but I'd like to have the 'more correct' method under my belt).
Can anybody help - does anybody have working code that can perform these operations ?
Perhaps I should post this in the Advanced OpenGL list but this seems a more appropriate forum to begin with.
Thank you for your time.