Use the Release from Point node to release rays from a set of points in a geometry. By default one ray is released at every selected point, although it is possible to release multiple rays at each point if the initial direction or an auxiliary dependent variable is sampled from a distribution.
See Release for information on the following sections:
Release Times, Ray Direction Vector,
Initial Ray Frequency,
Initial Phase,
Initial Intensity,
Initial Radii of Curvature,
Total Source Power,
Initial Polarization, and
Initial Value of Auxiliary Dependent Variables.