Wait, what's the difference between godrays and sunshafts?
Different names for the same visual phenomenon. Sunbeams, Jacob's ladder. Wiki has more info about it.
The technical differences,
mine is based on GPU gems 3 article.
I believe phal's using Farcry 2 techniques. But it is not very important because it is just a directional blur. Mine is not working in SM2.0 though. So phal's is more compatible. Also phal's can create a sundisc substitute. Which you can size or colored. Mine works on the texture you have. Phal's can cast the rays even sun is not visible on screen. Mine can't. Phal's is more complex being done by the guy who create the fabulous waves for MGE water, godrays was done by me, an amateur who only wrote a shader which creates black bars on screen(at that time!).
So even I use phal's shader, so I recommend you to use it too. The bright new sun is amazing. I am also working on my godrays shader, yeah, just to learn and fun and I have still cool ideas...
fine, I just want to get the torches and lamps to beam off rays like the sun would... please?
Both is for sun. But it can be done, I guess. Directional blur is costly. Applying to all lights sources would need a LOD system.
First needed things,
screen space positions of all light sources in screen.
world positions of them in depthbuffer, the accuracy would be a problem and performance of course... It is not likely.
Speaking of which, I want to say something,
all lights need billboarded bright glows. It is essential for bloom shaders to work correctly. If an experienced modder can create some assets we can see how it applies.