How can I have collisions as a point?

I’m using projectiles that need extremely small collision boxes, preferably a point. I do not want to create an extremely small collision box, but rather use a point. Does anyone know how I can use a point for collisions?

I assume using a sphere of radius zero would work. The best way to check for collisions between two spheres is to add their radii together and see if they’re closer than that, so a sphere of radius zero is the best way to do it. At least if you’re having it collide with spheres and capsules.

If you are using meshes, there’s theoretically better ways of doing it, but I can’t find anything about checking if a point is in a mesh or that sort of thing that’s built in to Unity. I recommend just trying a sphere of radius zero. If that doesn’t work, then just an extremely small sphere.