raytracing

I have a complex 3D scene that I need to display HTML elements on top of, based on a 3D coordinate. (I'm simply overlaying a div tag on top and positioning it with CSS.) However, I also need to partially hide it (e.g., making it transparent) when the 3D coordinate is obscured by a model (or phrased in another way, when it's not visible in the camera). These models may be have many hundreds of thousands of faces, and I need a way to find out if it's obscured that's fast enough to be run many times per second. Currently, I am using Three.js's built-in raytracer, with the following code: // pos =

I am currently working on ray-tracing techniques and I think I've made a pretty good job; but, I haven't covered camera yet. Until now, I used a plane fragment for view plane which is located between (-width/2, height/2, 200) and (width/2, -height/2, 200) [200 is just a fixed number of z, can be changed]. Addition to that, I use the camera mostly on e(0, 0, 1000) , and I use a perspective projection. I send rays from point e to pixels, and print it to image's corresponding pixel after calculating the pixel color. Here is a image I created. Hopefully you can guess where eye and view plane are

I've been working on my raytracer again. I added reflection and multithreading support. Currently I am working on adding refractions, but its only half working. As you can see, there is a center sphere(without specular highlight), a reflecting sphere(to the right) and a refracting sphere(left). I'm pretty happy about reflections, it does look very good. For refractions its kinda working...the light is refracted and all shadows of the spheres are visible in the sphere(refraction index 1.4), but there is an outer black ring. EDIT: Apparently the black ring gets bigger, and therefore the sphere

I am building a simple raytracer for educational purposes and want to add refraction to objects. Using Snells Law, I am able to create a new ray recursively at the intersection points. The raytracer supports currently only spheres and I use a scene where I have multiple spheres nested inside of each other with different refraction indices. If I start a ray from outside of the spheres, everything seems simple. You start with the refraction index of the scene, and as soon as you hit the first sphere, refract the ray using the refraction index before and the refraction index of the material of

I know kd-trees are traditionally used to store points, but I want to store lines instead. Would it be best to split the line at every intersection with the splitting of the kd-tree? or would storing just the end-points into kd-suffice for nearest neighbor finding? The kd-tree itself is designed for point objects. Not even for boxes, spheres or something like this. I believe you can somehow use a 6d tree that stores minx, maxx, miny, maxy, minz, maxz ; but I'm not entirely sure on how to query it correctly. The R*-tree (Wikipedia) might be a better choice here. It is really designed for

I'm implementing my own ray tracer as an iPad app for a school project. At the moment this is the result: I need to add the last requirement, soft shadows , but I can't find a complete reference anywhere. If I understood well, to implement this feature I have to shoot many ray from an intersection point to mt light source. This one must be an area light. Suppose I use a sphere, my questions are: Which point on the sphere I must use to calculate the shadow ray? How do I average the result? You are standing at a point P with local surface normal N, and need to find out the illumination arriving