» Mon Apr 04, 2011 6:01 am @palidoo: Yeah, not gonna use OGBEv1 or 2. Too large an impact on performance. Especially the AA.
What about AA? You're only going to impact performance if you choose expensive shaders in your shader load order. Besides, you're not going to get snow accumulation any other way. The method you describe with OBSE isn't even possible. Still not sure what you mean about AA but if you have an ATI card you can force AA on in the control panel just fine.
So is Skyrim's system an overlay or something else (shader? I wouldn't know...)? From the technical information that they posted, it seems that they scan the terrain with some sort of program/tool in order to detect the location of every mesh, then that sets boundaries for the rain so that it doesn't bleed through those meshes/perhaps accumulates on them.
The explanation from that article was awful. It was very poorly and non-technically worded. From what I've seen of the snow, they more or less "splat" the snow effect onto objects based on their normal maps. You can see this in Crysis snow levels (though the more impressive effect in that game is the actual snow in the air). The "artist-directed" component sounds like they essentially prevent the snow from "splatting" onto certain objects or maybe even specific areas of objects. The hint to that is how they said it was too uniform/even prior to this system they made. As you can see in Crysis, the effect often looks too uniform and even, and I don't believe there is any artist directed component in Crysis.
In any case the "system that scans the yadda yadda" they describe certainly has nothing to do with how the snow will appear in the sky. In Oblivion this was a camera space effect, hence it couldn't possibly ever have worked properly inside of exterior buildings or under overhangs. For them to fix this they'd need to move snow and rain into world space, and perform some kind of rudimentary collision testing. Because of the massive amount of snow/rain particles, the particles obviously aren't going to be sticking around very long and will most likely terminate on collision. Collision/termination or not, if it looks anything like the Crysis snow, I'll be pleased. It'd be better than Oblivion's simple screen effect that you see in screensavers or on websites during Christmas.
With OBGE, we're just short of implementing the same (ground) snow shader method they'll be using in Skyrim, sans artist-direction, which is funny considering we're a misfit band of hobbyists versing a AAA game. However, we don't actually have normal map information in the scene, just face normals, hence the geometry artifacting issues which Tomerk managed to solve with interpolation -- but at a cost to FPS. Covering the objects while having only the face normal information effectively erases any normal map detail, hence the artifacting. It uncovers how low-poly Oblivion actually is. But I'm afraid it's about as good as it's going to get for Oblivion, unless somebody wants to recreate (from scratch) Oblivion in Skyrim's engine.
