If you are modelling illuminating effect, most likely you will model the system under non-sequential mode and you could look up 9jX_Eoxy
^jUw4Dj~-q
Source Diode and Source Gaussian GN9kCyPK
XZM@Rys
to check if these two sources types support your source behavior. If they do then it should serve an good approximation for your light source.