I've been looking at the current master
source code, not a specific version : github commit b3ce68b4 on sept. 2019.
The source code is located in src/core/Raycaster.js
, and the doc is online.
A Raycaster
instance is constructed given a ray (origin point + direction vector) and a range on this ray (near, far distances), and offers the following API :
intersectObject( object, recursive, optionalTarget ) : Array