a technique for generating an image by tracing the path of light through pixels in an image plane and simulating the effects of its encounters with virtual objects
1
vote
1answer
85 views
Ray Tracing in 3D - generating a ray
A ray is shot from the camera eye to the camera screen at point (i,j) how do I get the coordinates of that point in 3D world coordinates?
The best I could find online is for point S
S = Q + au + bv
...
2
votes
2answers
104 views
Raytracer texture mapping (to triangle mesh) leaving artifacts
So I am trying to get OBJ loading working in my raytracer. Loading OBJs works fine, but I am having some trouble with getting the texture mapping working.
Here is an image of my result. It is ...
4
votes
1answer
150 views
What is the state of the art of ray tracing on the GPU?
I think ray trace rendering had to be done on the CPU for a long time. But since we have compute shaders in OpenGL 4.3 now, it might be possible to move the computations on the GPU and perform ...
3
votes
2answers
191 views
How does a point squared equal the radius squared?
I am working on a simple ray tracer but I don't understand some of the formulas.
One that is bugging me at the moment is this:
If a sphere is centred at origin, a point p lies on a sphere of ...
4
votes
1answer
94 views
Forcing early-z with raytracing
I'm working on a GLSL raytracer, and I need to be able to edit gl_FragDepth in the FS. However, doing so disables early-z culling. The scene is rendered front-to-back and the FS can only push points ...
0
votes
1answer
216 views
Ray Tracing Shadows in deferred rendering
Recently I have programmed a raytracer for fun and found it beutifully simple how shadows are created compared to a rasterizer. Now, I couldn't help but I think if it would be possible to implement ...
2
votes
1answer
116 views
Ray Tracing concers: Efficient Data Structure and Photon Mapping
I'm trying to build a simple ray tracer for specific target scenes. An example of such scene can be seen below.
I'm concerned as to what accelerating data structure would be most efficient in this ...
0
votes
3answers
377 views
Real-time ray tracing: How is it done?
I wonder what technology applications like Xara3D use to be able to perform real-time ray tracing.
How is such good quality rendering done in real-time?
2
votes
1answer
150 views
What is an easy way to work subsurface scattering into a raycaster?
I've got some neat effects with path tracing:
I want to add in an ability to do subsurface scattering, but I'm unsure of the general algorithm. With path tracing, it's:
foreach pixel:
trace( ...
6
votes
4answers
456 views
Impact of variable-length loops on GPU shaders
Its popular to render procedural content inside the GPU e.g. in the demoscene (drawing a single quad to fill the screen and letting the GPU compute the pixels).
Ray marching is popular:
This means ...
1
vote
1answer
347 views
Intersecting Ray with Extruded 2D Shapes (e.g. Extruded Text)
I'm looking for a way to find intersection between a ray and an extruded 2D shape or text (defied by a Bézier curve). Any ideas?
1
vote
2answers
159 views
Why Inverse Transform the Ray when doing Transformation?
I am adding 3D affine transformations to my ray tracer, and it seems all the literature on the web recommend inverse transforming the ray instead of transforming the 3D objects.
Why is that? There ...
1
vote
1answer
247 views
How to calculate the viewing cone radius at a distance in raymarching?
I'm "raymarching distance fields" (proper lingo: sphere-tracing) in GLSL. To implement cone-marching atop of it (and also to minimize the number of raymarching steps regardless of whether ...
3
votes
1answer
251 views
Procedural mesh generation from raytracer
I'm interested in applying the following technique:
Define game objects using a object definition DSL similar to what you would use for a raytracer (e.g. POVRay)
Use a specialised raytracer to ...
1
vote
1answer
252 views
Realtime rendering using a ray tracing engine
I want to render an object that has a mesh with one million hexagonal elements(100 * 100 * 100).
Lights, shadows and textures is not important and each element has a solid color.
and finally, the ...
0
votes
1answer
187 views
3D Huge mesh rendering
I am writing a program, that as input, I have a huge (10^6 elements) 3d mesh (with hexagonal shaped elements), and I want to realtime render it, but not as real-time as a game. It just can show the ...
5
votes
1answer
968 views
Fast pixelshader 2D raytracing
I'd like to do a simple 2D shadow calculation algorithm by rendering my environment into a texture, and then use raytracing to determine what pixels of the texture are not visible to the point light ...
0
votes
2answers
140 views
Which optional features would you recommend for a raytracer? [closed]
I'm developing a basic triangle mesh raytracer on a short deadline.
This means I can't implement every feature I come across, so I'm looking for some feedback about which features you think are most ...
