Paralax Mapping

[Domarius]

You gotta see this. Seriously.

 

http://graphics.cs.brown.edu/games/SteepParallax/

 

All the images in the row of 4 comparison images near

the start of the article are just a texture on a perfectly flat 2 poly plane.

 

The 3rd image from the left is the standard currently being implemented

in games. I think that's why the bricks in that morrowind screenshot

look so 3D.

 

Basically, bump maps and normal maps don't cut it. They create proper

light and shadow, but the raised surfaces don't obscure the lower

surfaces when you view them at an angle. Know what I mean?

 

With paralax mapping, you take the height map data from a bump map,

and then, I don't know how, but they use that to actually to somehow

render the surface how it should be, where some pixels will obscure

others - eg, in a stone brick wall with gaps between each brick, when

looking at it on an angle, the closest brick will obscure the gap

between itself and the brick beyond it. The bricks actually stick

out to overlap each other.

 

Of course, since it's still a mapping trick, once you see the very

edge of the actual mesh, its flat, but fuck, this looks real for the

most part. As usual, you pretty much ignore the edges when the rest

of it looks so damn real.

 

But in this document, they are doing "Steep Paralax mapping". I don't

know what it is or how its done, all I know is that image on the far

right looks BETTER than the actual texture - it nearly looks like a

photo!!!! Things are not only sticking out, but they are casting

shadows onto each other, and some thigns are sticking out a LOT

further than other things... also, its fast enough to implement in

games right now. WHEN. I want to see a game with this, it would look

so atmospheric....

[SneaksieDave]

It's part of the feature set* of Unreal Tech 3. Possibly Oblivion, too (can't remember the engine name) but I'm not sure about that.

 

Man, if id were to incorporate that into the D3 engine in a free update release, that would pretty much define "first-rate support." In fact, I sure hope they do, so D3 doesn't start to look old next to the next gen stuff. It's supposed to be infinitely extensible, so... cross yer fingers.

 

 

Edit: *to clarify, I meant standard (?) parallax mapping, not this "steep" thing.

Edited June 7, 2005 by SneaksieDave

[Springheel]

I'm pretty sure I already saw someone posting parallax mapping examples on D3W.

 

edit: http://www.doom3world.org/phpbb2/viewtopic...hlight=parallax

 

Looks like it's been around for a while, though it doesn't always look right under certain lighting conditions.

[SneaksieDave]

[Renzatic]

That parallax mapping plugin is old news, get with the times and check out D3 Relief Mapping!

[god_is_my_goldfish]

That parallax mapping plugin is old news, get with the times and check out D3 Relief Mapping!

Good god! Is there any way we could use that?!

[Renzatic]

Yeah, we could pop it right in and make heightmaps using ORB. It'd make all our textures look like actual 3D geometry...only problem is the game would only run at 2 FPS or so.

 

It might be something nice to use in a couple of years or so, but right now it's too slow to really be a viable option.

[Bhruic]

According to the guy who made the video, he was getting around 50fps. Admittedly with some high-end equipment.

 

Still, it might be nice as an option for people who do have said equipment.

[AtariThief]

Please go here

 

It should shed a little light...

Oh and try the pdf.

Edited June 9, 2005 by AtariThief

[Domarius]

AtariThief, that is standard paralax mapping. The link I posted has Steep Paralax mapping, which if you check out the link, looks more realistic that the actual texture they used...

 

 

Standard paralax mapping is being used in modern games already apparently.

[RazorBladder]

Although geometry looks convincing enough, I think we may have to be careful as the more illusion of 3d geometry that's generated from the textures, the more quality itself seems to be put at risk.

 

Also the relief mapping that fpo had made distorts horribly at angles, though he says there's a lot of optimisation he can do so i look forward to that. However AFAIK, the feature seems to only support nvidia cards due to the supposed requirement of a very large number of, mostly dependant, texture look ups to which ATI cards only supports 4 in a single shader.

[Spitter]

Pretty, but I wonder how it looks like close-up. If it's still just a texture trick, it might be a bit... flat.

[Domarius]

It moves correctly when you move. The only give away is if you see the very edge of the wall, nothing will stick out over it because it is the edge of the polygon.

 

But that is only the very edges. Look at that screenshot and tell me it looks flat...

[sparhawk]

And collisions will also not work. So if this is an extrusion which is large and you walk into it, you can not detect the collision. Apart from that it really looks cool.

[obscurus]

I think it looks great - as long as you use it carefully, and add trim at the edges of walls etc, and don't overdo it, I don't see any problems with it... I'd like to see the D3 relief mapping in use on the Dark Mod, It would really make those castle walls look special...

 

That said, I know for the Unreal 2 and engine, and I would say maybe for for D3 as well (though I'm guessing, and D3 has a completely different lighting engine), that it is computationally cheaper to use more polygons than loads of textures... Just look at how much higher the poly count is in UT2K4 compared to D3. So you might be better off making walls with lots of bricks made of actual geometry and plain old normal maps than loading all those extra paralax texture maps into your graphics memory (that would of course involve more work for the modeller/mapper though). Polygons take up a small amount of memory compared to 32 bit textures, and graphics cards these days can deal with a huge number of polygons... Just a thought.

Edited June 23, 2005 by obscurus

[Domarius]

Well, it's not well founded... parallax mapping doesn't require any more textures than normal mapping (one for colour, one for the 3D info). Polygons are the first place to cut down on when you want speed. Most of the beautiful surfaces you see in D3 are only done with a few polygons. More textures just take up more memory. The same texture drawn on two different polys still has to be drawn differently on each, so it's twice as much work than if it was one poly.

 

The general rule in 3D game design is to use as few polys as possible and put most of your work into the textures. Take the Imp in Doom 3 for example. If you look at it in the editor (where it just uses a flat generic red texture), you can see that it's mouth area (everything in the lower half of the face) is just a flat trapezoid. When you shine the torch into its face, you can see right down it's throat in 3D and see its glistening tongue - this is all the work of the normal map (depth of the mouth), the gloss map (glistening tongue), and the colour map (colour and other details accentuated by the normal map).

 

So you might be better off making walls with lots of bricks made of actual geometry and plain old normal maps than loading all those extra paralax texture maps into your graphics memory (that would of course involve more work for the modeller/mapper though)

You need that high detail model to generate normal maps in the first place, so it wouldn't actually be any extra work.

 

...graphics cards these days can deal with a huge number of polygons.

...but they are used sparingly and effectively in conjunction with textures to create the cool scenes you see in the screenshots of the next upcoming game.

It's the same thing as optimising algorithims in programming. "Why do you want to save that one multiplication? We're not working on 286's anymore" "Because when I do that multiplication 1000s of times, the latest CPU starts to slow down. If I optimise this, I can have 500 guys running around instead of 50". More power doesn't mean you waste it, it means you can do even cooler things if you use it as effectively as before.

 

 

 

In other news, some guy at www.flipcode.com just tweaked the standard parallax mapping algorithm to get more detail with not much in exchange for performance (click on the image links in the first post)

http://www.flipcode.com/cgi-bin/fcmsg.cgi?thread_show=25429

Edited June 23, 2005 by Domarius

[obscurus]

Oh... I was kinda under the impression that more maps were required for paralax mapping, but I might have misread the forums (or fora for the latin purists) on the subject...

 

There are static meshes in UT2K4 that have as much apparent detail as some of the normal maps in Doom 3, I suppose there may be some diferences in the engines in terms of whether they are biased towards large poly counts over lots of texture maps. In UT2K4 the majority of the textures are a diffuse map with sometimes a detail texture that breaks up the pixellation when viewed up close, so it is using much less multitexturing than D3 uses. UT I guess is more optimised for higher poly counts..

 

Of course, Unreal Engine 3 uses parallax mapping and extensive multitexturing AND collossal poly counts - have a look at some of the wireframe screenies at the Unreal Technology website http://www.unrealtechnology.com/screens/EmbryWire.jpg

This beast of a game will need the new nVidia GeForce 7800 GFX at least I would say...

 

 

I suspect that the Doom 3 engine can probably cope with more polys than Doom 3 has, I think the reason D3 has lower polys has something to do with it being quicker for mappers to make simple geometry with complex textures, rather than a limitation of the engine, but I could be wrong.

 

Regardless, I think parallax/steep parallax/relief mapping is a good thing, and should be included in The Dark Mod if at all possible :

 

 

Edit: I forgot about UT2K4's lightmaps and specular maps - hey there is a fair bit of multitexturing afterall.... Oops

Edited June 23, 2005 by obscurus

[BlackThief]

This beast of a game will need the new nVidia GeForce 7800 GFX at least I would say...

not really - unreal 3 is developed on a geforce 6800ultra

 

Interview with Tim Sweeney from epic

 

Freeman: And will a 6800 Ultra be able to run Unreal Engine 3 with all the options maxed at 1024 by 768?

 

Sweeney: Yeah, 1024 by 768 should be perfect for an Ultra, of course by the time Unreal Tournament 2007 ships at the middle or the end of next year, you'll have even higher-end cards than that; you'll have four times the performance, so you'll be able to run 1600 by 1200 on those.

 

(http://forums.beyondunreal.com/showthread.php?p=1818720)

[obscurus]

But I suspect a 6800 will be closer to the minimum hardware requirement, so I don't think I would be far wrong in saying it would be preferable to have a 7800 or higher for optimum framerates and visuals... I imagine UE 3 will look nice and be playable on current high end hardware, but the newer hardware will really improve the quality IMO. The 7800 also has optimisations for parallax mapping and virtual displacement mapping, which UE 3 uses a lot of, so I suspect the performance boost will be substantial...

 

If you look at http://www.unrealtechnology.com/screens/RagDoll.jpg

you can see just how much depth and detail the virtual displacement mapping has in UE 3 - you can actually see the bricks projecting out at the bottom of the wall, and casting shadows on the floor... displacement mapping in action

[Dram]

Well, either way, I don't think my 6600GT will be able to handle it on full graphics

 

Do I hear "Upgrade"?

[obscurus]

With a kid on the way, that upgrade is gonna be a while away for me

[sparhawk]

Games are ALwAYS done with a margin of backward compatibillity. So if the devs work with a 6800 it doesn't mean that this is the lowest card they will support. Quite on the contrary, I ratehr expect this to be the middle or optimum card to be used.

[obscurus]

Games are ALwAYS done with a margin of backward compatibillity. So if the devs work with a 6800 it doesn't mean that this is the lowest card they will support. Quite on the contrary, I ratehr expect this to be the middle or optimum card to be used.

 

That is not what the Unreal Technology website says - they have explicitly stated that they have taken out backward compatability with older hardware, it will only run on Direct X 9 cards with a LOT of grunt, I think even a 6600 GT will struggle...

 

Unreal has broken with tradition here to make a game fully optimised for the latest hardware, that definately will not run on machines built before 2005...

[sparhawk]

By the time they will release it, this will no longer be true, unless they release within the next few months.

[obscurus]

Well, as far as I know it is planned for release sometime in late 2006, so 6800 level cards should be pretty affordable by then. I did read an interview with Tim Sweeny that UE3 will require the dev hardware (ie 6800 GT) as pretty much the minimum specs though... It apparently runs at about 25 fps on the development hardware, which is playable but nowhere near the 72 fps optimum ( =http://www.gamedesign.net/node/829]http://www.gamedesign.net/node/829 ), so you are going to want hardware released in 2006 to get the best experience (or an XBox 360)..

Edited June 26, 2005 by obscurus