Most sound sources are a point. How to use Panda3d’s audio3d to achieve 3D effects with solid volume such as rivers and lakes
First of all, greetings, and welcome to the forum! I hope that you find your time here proves positive for you!
As to your question:
Well, the simplest approach–the one that I tend to use in games–is to find the nearest point on the river (or other such object) and to place the sound there; that usually works well enough, I find.
However, if that’s insufficient–as may well be the case in VR, for example–what might work is to find not only the closest point, but also two or four other points on the river spaced out a little distance to either side of the closest point, and to then place additional sounds at those locations. (This might call for using variations of the base sound, in order to prevent the audio from becoming too uniform.)