Notice anything? If I understand your code correctly, you might want to try: r. Sorry for the late reply. Finally how does the code you gave me solve it? Sorry it took me so long to reply. Moving on though, this means that we have found the value for tc:. So a more detailed explanation would be highly appreciated. Congratulations to our 29 oldest beta sites - They're now no longer beta!

The geometric solution to the ray-sphere intersection test relies on simple maths.

## mathematics Fast Ray Sphere collision code Game Development Stack Exchange

Changing the value for t makes it possible to define any position along the ray. . Before we see how to implement this algorithm in C++, let's see how we can. Intersects ray r = p + td, |d| = 1, with sphere s and, if intersecting, hacks (ie.

with infinite precision real numbers, the algorithm below is exactly.

### c++ Intersection problems with raysphere intersection Stack Overflow

which is an equivalent of dot((P−C),(P−C))=r2 where P is the point on the When the ray and sphere intersect, the intersection points are.

I will write the parametric equation for a point on the ray three different ways, and explain each, just to make sure the concept is clear. These three special cases correspond to three different scenarios where a ray may miss the sphere entirely 0 solutionsmay graze the sphere tangentially at one point 1 solutionor may pierce the sphere, entering at one point and exiting at another 2 solutions.

I looked at Real Time Collision Detection book but it doesn't seem to have it either.

Video: Ray sphere intersection c code switch OpenGL (SDL,C++) tutorial 16 - ray tracing (ray-sphere intersection)

Email Required, but never shown. We have already discussed how the ray tracing algorithm looks for intersections between camera rays and solid objects. As the title of this post suggests, the end product of this post will be a function which will take a ray and a sphere, and return both if the they intersect, and if so, the location of the intersection s.

I also added the third case that you mentioned.

If the ray origin is inside the sphere, it's possible for t0 to be negative the fewer special cases you have, the easier it is to check your code.).

This is an important calculation.

Sorry for the late reply. And the fewer special cases you have, the easier it is to check your code. Just want to mention though that it didn't change the underlying problem I had which was solved by Benny Smith's answer.

So we have.

Right now, you've positioned the camera one unit away from the screen, but the rays can shoot as much as units to the right and down. I've created a Ray and Sphere class and then a function in my main file which goes through each pixel to see if there's an intersection relevant code will be posted below.

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So, in order to get the locations of the P0 and P1, all we need to do is find the correct t value for each of them. All Rights Reserved.

Much better!

Moving on though, this means that we have found the value for tc:.