I'm not sure how the fact it's *directional* plays into the *shadows*. I understand how it plays into lighting, but shadowmapping pretty much works the same, doesn't it? You still need to have a light source position to render the shadow depth texture from? And I'm guessing the shadows for something like in the youtube video I linked is done an a single shadow pass... actually hmm
now that I think about it, i guess if it's static geometry it's possible to use baked lightmaps for the geometry and then just separate individual shadow maps for each moving object (player), although I somehow don't think this is what the tech in the video is doing, for example with modern engines that have this type of "full shadowing", with things like dynamic geometry or many many objects, or even dynamic time of day, I doubt they use a separate individual shadow map per object?
A lightmap wouldn't work in that situation, and individual shadow maps would probably be too slow, plus, for something specifically like time of day... the "entire" geometry has dynamic shadows, so again I don't get how that would be created since you need to render a shadow depth texture from a specific light source position??