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User talk:Neo: Difference between revisions
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::::As for "question 1", you can call those character shadows shadow-mapped if you want, but as far as I can tell they have nothing to do with textures and UVs generated at runtime (which is what shadow mapping is about). To me, it definitely looks like the sphere tree of the character is projected downwards onto a grid, and the grid squares are then shaded with decals placed at fixed positions, switched on and off. The alpha amount of the squares is apparently not proportional to the amount of overlap: this allows for an evenly shaded interior, but the edge is fuzzy. The grid is quite coarse throughout the trailer, but it is much finer in the multiplayer arena at 1:37, for example: in that scene you can also see that since the projection is that of an upright sphere tree, for increasingly fine grids the shadow will look more and more like a circle. In that sense, the single dynamic decal that we have now is a consistent improvement over whatever those "shadow maps" were: it looks just like a super-high-resolution "shadow map", only smoother. Also note that the Iron Demon doesn't have a shadow at all in that trailer, so whatever shadow map was being computed from its sphere tree, it probably sucked. | ::::As for "question 1", you can call those character shadows shadow-mapped if you want, but as far as I can tell they have nothing to do with textures and UVs generated at runtime (which is what shadow mapping is about). To me, it definitely looks like the sphere tree of the character is projected downwards onto a grid, and the grid squares are then shaded with decals placed at fixed positions, switched on and off. The alpha amount of the squares is apparently not proportional to the amount of overlap: this allows for an evenly shaded interior, but the edge is fuzzy. The grid is quite coarse throughout the trailer, but it is much finer in the multiplayer arena at 1:37, for example: in that scene you can also see that since the projection is that of an upright sphere tree, for increasingly fine grids the shadow will look more and more like a circle. In that sense, the single dynamic decal that we have now is a consistent improvement over whatever those "shadow maps" were: it looks just like a super-high-resolution "shadow map", only smoother. Also note that the Iron Demon doesn't have a shadow at all in that trailer, so whatever shadow map was being computed from its sphere tree, it probably sucked. | ||
:::::[[User:Geyser|geyser]] 19:19, 21 October 2008 (CEST) | :::::[[User:Geyser|geyser]] 19:19, 21 October 2008 (CEST) | ||
::::::Not sure we really want an in-depth discussion about this on Neo's talk page, but if you like we can move it to somewhere else; for now I'll respond here, since you asked here... | |||
::::::*"What crappy shadows?" Any of them, pretty much. But if you need visual aids, let me ask you what the heck is going on [http://iritscen.oni2.net/temp/Oni-BadShadows1.jpg here], let me point out that many shadows are of [http://iritscen.oni2.net/temp/Oni-BadShadows2.jpg erratic shadiness and height], and some crates are lacking shadows completely in the back of that last shot. Also, count the things wrong [http://iritscen.oni2.net/temp/Oni-BadShadows3.jpg here]. Finally, Gumby contributed an example the other day: explain why the shadows move [http://iritscen.oni2.net/temp/Oni-BadShadows4.jpg towards the light] if they're not crappy. You yourself already acknowledged that the baked-in shadows were not good, so I can't understand your sudden puzzlement, but there ya go. | |||
::::::*"As far as I can tell [etc. etc.]". As far as I can tell, you haven't been looking very hard. If you wanted to be lazy you could have just asked me on YIM for evidence, but I guess I have to take up more space on this page to answer the question you posted here: [http://iritscen.oni2.net/temp/Marathon-GoodShadows1.jpg these lights] [http://iritscen.oni2.net/temp/Marathon-GoodShadows2.jpg are dynamic]. Some lights even flicker in and out, with the expected changes in shadowing. And even though this is from the OpenGL-powered port, they looked exactly the same in 1994 when the game came out. Now, it's true that those are dynamic lights, not dynamic shadows, and they are in a hard-edged style not a softened style, but I just wanted to illustrate how much nicer Marathon's interplay of light and darkness is than Oni's. My question was why Oni couldn't do those sorts of calculations dynamically too. Don't jump all over me. | |||
::::::*Re: How the shadow mapping works. We are saying close to the same thing here. I don't dispute/care how the shadows are calculated from the characters' models, I just think they are generated on-the-fly, not being applied as decals. Decals are fixed images stored in a resource file, whereas these look more like shaded boxes being filled in on a grid using vertices (also you called out current shadow "dynamic", and it's the opposite, it's static). It would be very non-standard to use static decals for shadow mapping, but whatever. I don't argue Oni would have looked better as it was back then. If we could bring back that technology from within the code (which we probably can't, this is just a hypothetical sentence so don't flip out), then we could probably also increase the grid resolution and make it look nicer; otherwise it is just something I pointed out for the sake of pointing it out. And it's true that the ID didn't have the shadows, that's interesting. | |||
::::::--[[User:Iritscen|Iritscen]] 21:30, 21 October 2008 (CEST) | |||
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