int  pcline(<geometry>geometry, string PChannel, vector P, vector dir, float max_distance, int maxpoints)
int  pcline(<geometry>geometry, string ptgroup, string PChannel, vector P, vector dir, float max_distance, int maxpoints)
When running in the context of a node (such as a wrangle SOP), this argument can be an integer representing the input number (starting at 0) to read the geometry from.
Alternatively, the argument can be a string specifying a geometry file (for example, a
.bgeo) to read from. When running inside Houdini, this can be an
These functions open a geometry file and return a list of points within max_distance of the line passing through P with direction dir.
ptgroup is a point group that limits the points to search. This is a SOP-style group pattern, so can be something like
@Cd.x>0.5. A blank string is treated as matching all points.