# Questions tagged [ray]

The tag has no usage guidance.

12 questions
197 views

### How to calculate ray

In ray-tracing technique critical point is to calculate rays which came out from eye $E$ to target $T$ through pixel $P_{ij}$ on viewport. The "viewport" is represented as rectangle divided to square ...
110 views

### ray-triangle intersection precision - c++

I'm building a software renderer but I think there might be some problem with my ray-triangle intersection accuracy. I implemented the algorithm referring to ...
64 views

### How to raytrace triangular faces when camera is not at origin?

I've watched the Pixar In A Box, Maths of Rendering Tutorial on Khan Academy. I've started writing a raytracing program and have come to the point where I must solve for ...
119 views

### Self intersection artifacts in 3D image raytracing

I am developping a voxel raytracer for global illumination. I have been successful in multiple aspects but there is a problem I am not sure how to solve. The model works as most other Voxelization ...
152 views

### Classify acceleration structure using surface area heuristic

My professor gave me the following example exam question: Given 4 spheres with diameter = 1. Their centers are located on coordinates (2,4,0), (4,2,0), (4,6,0) and (6,4,0), as seen in the ...
59 views

### Expected visibility

I want to extend the following to work on a solid angle: Suppose we have a volume filled with small surfaces. If we cast a ray from a given point, the probability that the ray will not hit a surface ...
200 views

### What's the concept of “Ray” really?

I'm learning Ray Tracing using this MIT tutorial. I've heard Ray Tracing only in the context of lighting. I.e. I understand that ray casting is used to light an object that has been already drawn. ...
234 views

### Sending shadow rays to the sun

How is sun modelled for ray tracing rendering? Is it part of the scene, like a sphere with a centre in some far location or it is just considered as a point? Also regarding sending shadow rays to the ...
318 views

### How can i make my ray tracing algorithm fast in terms of intersection testing?

I am working on a ray tracer. But i want to put more than 10 objects in the scene. How can i make the intersection fast so that it can give me reasonable FPS. Its a cpu-based ray tracer.
200 views

### Is there a difference between window and screen in computer graphics?

I've been reading some code which setups a ray tracer and I've realized I've a doubt regarding what's a screen and what's a window in this context. Here's the relevant code using Qt: ...