Computer Graphics Stack Exchange
Computer Graphics Stack Exchange

Questions tagged [raytracing]

Questions specific to raytracing (as opposed to scanline rendering), the 3D graphics technique of intersecting rays from the camera with objects in the scene.

See also:

424 questions
42
votes
2 answers

What is Ray Marching? Is Sphere Tracing the same thing?

A lot of ShaderToy demos share the Ray Marching algorithm to render the scene, but they are often written with a very compact style and i can't find any straightforward examples or explanation. So what is Ray Marching? Some comments suggests that it…
psicomante
  • 600
  • 1
  • 4
  • 11
36
votes
3 answers

Why does monte carlo ray tracing perform better than distributed ray tracing?

I've heard that the quality of a monte carlo ray tracer (based on path tracing algorithms) is much more realistic than a distributed (stochastic) engine. I try to understand why, but I'm just at the beginning. In order to dive into this topic and…
p2or
  • 596
  • 1
  • 7
  • 15
30
votes
2 answers

Path tracing the Cook-Torrance BRDF

-- Sorry for the long post, but I prefer to do that way because "Devil is in the details." :) I am writing a path tracer from the scratch and it is working nicely for perfectly diffuse (Lambertian) surfaces (i.e. the furnace test indicates - at…
user5681
25
votes
1 answer

Anti-aliasing / Filtering in Ray Tracing

In ray tracing / path tracing, one of the simplest way to anti-alias the image is to supersample the pixel values and average the results. IE. instead of shooting every sample through the center of the pixel, you offset the samples by some…
RichieSams
  • 3,652
  • 24
  • 35
21
votes
5 answers

How to raytrace Bezier surfaces?

I tried this question on math.SE and surprisingly, the answer was "the equations are too nasty, just feed the function it to a numerical root-finder". But if you consider yourself "a graphics guy" like me, and have played extensively with Bezier…
luser droog
  • 1,328
  • 2
  • 12
  • 27
21
votes
2 answers

How do correlated samples influence the behavior of a Monte Carlo renderer?

Most descriptions of Monte Carlo rendering methods, such as path tracing or bidirectional path tracing, assume that samples are generated independently; that is, a standard random number generator is used that generates a stream of independent,…
Benedikt Bitterli
  • 2,575
  • 15
  • 20
19
votes
1 answer

Why is recursion forbidden in OpenCL?

I'd like to use OpenCL to accelerate rendering of raytraced images, but I notice that the Wikipedia page claims that recursion is forbidden in Open CL. Is this true? As I make extensive use of recursion when raytracing, this will require a…
trichoplax is on Codidact now
  • 6,222
  • 2
  • 22
  • 67
19
votes
3 answers

What's the current state-of-the-art algorithm for ray-tracing height-fields?

There have been lots of papers over the years on different techniques for drawing height-field terrain in a ray-tracer. Some algorithms ray-march the grid directly (or via a quadtree); others transform the terrain into a polygon mesh and use a…
Dan Hulme
  • 6,600
  • 1
  • 15
  • 35
17
votes
2 answers

Subpixel Rendering for a Ray Tracer

In font rendering, it is common to use subpixel rendering. The basic idea here is to break the pixel into its RGB components and then compute a value for each separately. Since each component is smaller than the entire pixel, higher quality…
imallett
  • 1,870
  • 10
  • 23
16
votes
1 answer

Progressive Path Tracing with Explicit Light Sampling

I understood the logic behind the importance sampling for the BRDF part. However, when it comes to sampling light sources explicitly, all becomes confusing. For example, if I have one point light source in my scene and if I directly sample it at…
Mustafa Işık
  • 397
  • 3
  • 8
15
votes
1 answer

Difference between BVH and Octree/K-d trees

So I'm currently reading up on acceleration data structures and so far I've heard there are 2 main schemes. Object Subdivision and Spatial Subdivision. The Bounding Volume Hierarchy belongs to the Object Subdivision approach and K-d/Octree belong to…
gallickgunner
  • 2,353
  • 1
  • 10
  • 32
15
votes
4 answers

How is Anti Aliasing Implemented in Ray Tracing?

After reading a few articles online I can confidently say I am clueless on how Anti-Aliasing works when using Ray Tracing. All I understand is that A Single Pixel/Ray is split into 4 sub-pixels and 4 rays rather than 1. Could somebody please explain…
Arjan Singh
  • 2,463
  • 3
  • 20
  • 37
15
votes
1 answer

Radiosity VS Ray tracing

Radiosity is basically what allows this: In a tutorial of Cornell University about Radiosity it is mentioned that: A ray-traced version of the image shows only the light reaching the viewer by direct reflection -- hence misses the color…
Armfoot
  • 615
  • 1
  • 6
  • 14
15
votes
2 answers

How to build a decent lens/camera objective model for path tracing?

I have written a small path-tracer after learning and experimenting on smallpt. The only thing that I did not write (and understood) myself is how the initial rays are computed and fired from the camera. I got the principle right, but I'm looking…
teh internets is made of catz
  • 345
  • 2
  • 7
15
votes
3 answers

Non Real Time Raytracing

I've played with real time raytracing (and raymarching etc) quite a bit, but haven't spent that much time on non real time raytracing - for higher quality images or for pre-rendering videos and the like. I know one common technique to improve image…
Alan Wolfe
  • 7,711
  • 3
  • 29
  • 72
1
2 3
…
28 29