If I had to take a guess, the three images you linked showcase 3 different ways of doing god rays. You can set up a sun light and tweak post process/world process settings to get natural god rays, but sometimes you’ll want to take it a step further and make a particle to assist in the process.
If you open the blueprint examples project you’ll find a pretty awesome blueprint that shows you how to take a light shaft particle and have it match the angle of your current “sun” angle, so that when you move your sun (either dynamically during the game or just messing around in the editor) the god ray angle follows. I wouldn’t consider this a solution if you want god rays in a wide expansive forest (for that you’ll just need to tweak post process settings, which someone else can chime in for), but this works great for emphasizing sun through windows and hard surface openings (i.e. a hole in the roof of a building).