I am trying to achieve something I've seen numerous times, but I don't know where to start from. I've come across numerous old effects, which I can't recreate. The said effects are the glow animations seen here: world of warcraft armor sets or for instance here Diablo glowing wings. In my desperation I even tried to contact blizzard, but with no success.
My common logic tells me these effects are not implemented with particles as that would be too expensive, especially on the hardware WoW ran on. On top of that, these looks strangely static, in a way even 2-D. I suspect something to do with images. I'm only a hobbyist graphics programmer(on top of that, not a good one) and I can't wrap my head around it. I would really appreciate any help.