Ray-box intersection calculator
>>>> WARNING: very poor translation!!! <<<<
Recently I've seen Danyk's 3D x-ray videos like this one:
Even if the quality of the record is not very impresive it seemed to me like possible source of data for cone-beam backprojection which is an algorihtm for reconstruction of 3D voxel volume model from 2D projections. Current results of my little experiment with backprojection can be seen for example here:
Backprojection is quite trivial in principle but it envolves some linear algebra. I got stucked at a basic problem: Ray-box intersections. There are bunch of algorithms that tells you if the ray is intersecting a box but none of them says where exactly (at least I haven't found one). I was a bit desperate so I've made a little tool that visualises the problem for easier debugging. The tool and its source codes are available if you wish to see my solution of the problem.
The program sends rays from focal point to every point in defined mesh grid which represents
the screen or projection. The ray sections that intersects the box are drawn with red color (the box
represents voxel volume).
The program also allows to change camera view angles for easier orientation.
(c) 2013, Stanislav Mašláň - All rights reserved.