raytracing

How do I calculate the intersection between a ray and a plane? I have been visiting every possible website I can find and this is what I have achieved so far: float denom = normal.dot(ray.direction); if (denom > 0) { float t = -((center - ray.origin).dot(normal)) / denom; if (t >= 0) { rec.tHit = t; rec.anyHit = true; computeSurfaceHitFields(ray, rec); return true; } } This does not work :s My function input is: ray: that contains origin and direction. rec: a container class for storing hit information (bool, t, etc) My function has access to the plane: point: the point that defines the plane

I'm currently implementing a raytracer. Since raytracing is extremely computation heavy and since I am going to be looking into CUDA programming anyway, I was wondering if anyone has any experience with combining the two. I can't really tell if the computational models match and I would like to know what to expect. I get the impression that it's not exactly a match made in heaven, but a decent speed increasy would be better than nothing. Matt J One thing to be very wary of in CUDA is that divergent control flow in your kernel code absolutely KILLS performance, due to the structure of the

I have to apply a spherical filter on a image in android, I have attached input and expected output image. Output image will be processed from the squared centered region of input image and mapped it to sphere. Any idea how to do this in Android. Will I have to use openGL for doing this or 2D-trasformation alone will do the task. strike the following code Fish Eye lens for creating the Sphere and apply some modifications for scaling the sphere and background generation, it will work mostly for square images. Brad Larson I just got an implementation of this working using OpenGL ES 2.0 on iOS:

I am trying to implement the algorithm explained on this paper, used to traverse grid cells in order following a straight line, which is useful for ray tracing: http://www.cse.yorku.ca/~amana/research/grid.pdf The paper describes the algorithm as two parts: initialisation and iterative traversal. I can undersand the iterative traversal part, but I'm having trouble understanding how some of the variables in the initialisation part are calculated. I need help initialising tMaxX , tMaxY , tDeltaX & tDeltaY . Their initialisation procedure is explained as follows: Next, we determine the value of t

I'm doing a raytracer hobby project, and originally I was using structs for my Vector and Ray objects, and I thought a raytracer was the perfect situation to use them: you create millions of them, they don't live longer than a single method, they're lightweight. However, by simply changing 'struct' to 'class' on Vector and Ray, I got a very significant performance gain. What gives? They're both small (3 floats for Vector, 2 Vectors for a Ray), don't get copied around excessively. I do pass them to methods when needed of course, but that's inevitable. So what are the common pitfalls that kill