Use the Release from Grid feature to specify the initial positions of rays using a grid of points. It is useful to release rays from a grid when the initial ray position is known exactly. A grid-based release may be used, for example, when rays are released from the focus of a lens or when a system is excited by a laser. This is the easiest way to release rays from known locations in the void region outside the geometry.

As an alternative to typing points into a text field, you can load them from a file. The Release from Data File node can be used to import the initial ray positions and directions from a text file.