在3D空间中获得声音的“声像”

Question

I am currently writing a simple 3d sound system, but I got stuck.

The problem is: I have a point in the space, where the sound comes from, and of course I have the listener, with his point and orientation.

The distance was not the problem, it works perfectly, but when I want to calculate the pan of the sound (how much left/right), well it is a total disaster.

I have searched it on the internet, but I can't find any usable solution, and then I tried to calculate it by myself with triangles and stuff, but you don't want to know what the result was.

I won't show code, because I have written it three times, and each version was unusable.

I don't want you to necessarily give me code, I will happy if I get a mathematical solution for that. I would like to get if the sound is how much left or right from the camera.

I work in c++ 11 and the sound library is Audiere.

Edit: Thanks to willywonkadailyblah I figured out some solution. You can watch it here: Get x position of sound from camera

with the dot product I can get the cos alpha of the triangle then with a simple pitagoras theorem I can get the distance (A).

And in the end I divide the pandistance with the heardistance and multiply with the sound distance.

Answer 1

You could calculate the dot product of the camera direction and the vector joining the camera and the sound source. This gives the cosine of the angle between the vectors. If the dot product is closer to zero than one, the sound source is more "to the side" than "in front".