So I'm creating a UFO, but I want to create that eerie transparent light when they're abducting someone. This is the best that I've come up with, but the light doesn't exactly go through all the way down when it's rendered. Does anyone know a better way to create this?
Another way to create a volumetric light beam (without the need of volume container) is to connect the output of an emission shader to the volume input of the material.
Multiply node controls the strenght of the beam, gradient texture creates light falloff, mapping node for sizing and placing the effect.
One way to do this would be to use a Color>Light Falloff node with the emission material you have assigned to the underside of your ufo.
To begin, you will need to create a container for the volume as it seems you have already done. Mine is a circle extruded downward.
For the containers material simply use a volume scatter shader connected to the volume input of the material output. Adjust the density as needed.
For the emission material, add a color>light falloff node to the strength input of an emission shader. Adjust the strength and smooth values as needed. The setup I used is as follows:
This is my result, not perfect but should get you going: