A showcase of a volumetric lighting technique in ROBLOX that I figured out how to do years ago. This is done entirely within ROBLOX and is a relatively basic technique.

Performance:
For me it runs at 60FPS ingame, but obviously results will vary depending computing power and a number of other factors, like density between the beams, the range of the beam box, whether there is proper camera culling, scene complexity, etc.

PC specs:
i57600k @ 3.80GHz
GTX 1060 6GB
16GB DDR4 ram @ 2400MHz

0:00 Introduction
1:50 The concept
4:58 Connecting it to the camera
5:31 Potential optimizations
6:11 Removing excessive beams
7:13 Mitigating artifacts
7:56 Lights
8:18 Caustics prototype
9:03 Screenshot slideshow