Bump Mapping

Afr · August 2004

<div class="IPBDescription">In half life, yes its true.</div> Taken from <a href='http://www.valve-erc.com' target='_blank'>www.valve-erc.com</a>

</div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><b>QUOTE</b> </td></tr><tr><td id='QUOTE'>Bump mapping is quickly becoming the “big thing” that every new game must have. It adds detail where there was none before, and provides a much enhanced visual experience. Games are almost relying on it to give their visual intensity; a good example of this is Doom 3.
</td></tr></table><div class='postcolor'>

<img src='http://collective.valve-erc.com/data/docs/1091469531-97736200/files/bump2b.jpg' border='0' alt='user posted image' />

<img src='http://collective.valve-erc.com/data/docs/1091469531-97736200/files/bump3b.jpg' border='0' alt='user posted image' />

The screenshots speak for themself dont they <img src='http://www.natural-selection.org/forums/html//emoticons/tounge.gif' border='0' style='vertical-align:middle' alt='tounge.gif' />

The article can be found <a href='http://collective.valve-erc.com/index.php?doc=1091469531-97736200' target='_blank'>HERE</a>.

Drfuzzy · August 2004

I get the feeling that this is hl maps in doom3 or something <img src='http://www.unknownworlds.com/forums/html//emoticons/tounge.gif' border='0' style='vertical-align:middle' alt='tounge.gif' />

But, i wana have this if its real, could make models look darn sexy <img src='http://www.unknownworlds.com/forums/html//emoticons/biggrin.gif' border='0' style='vertical-align:middle' alt='biggrin.gif' />

Afr · August 2004

I would like to know how it affects your fps <img src='http://www.unknownworlds.com/forums/html//emoticons/tounge.gif' border='0' style='vertical-align:middle' alt='tounge.gif' />

Anyway it would look cool in some areas of the ns maps.

Drfuzzy · August 2004

Well, if this isint fake i wana see it in ns, or atleast a option in the future <img src='http://www.unknownworlds.com/forums/html//emoticons/biggrin.gif' border='0' style='vertical-align:middle' alt='biggrin.gif' />

sawce · August 2004

It looks nice, but read the problems section:

</div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><b>QUOTE</b> (Problems/Issues/Caveats/Gotchas)</td></tr><tr><td id='QUOTE'>

Firstly, as mentioned above, anything that isn’t a world brush will not have bump mapping applied. There is probably a way to get this working for brush entities, but the only way I can think of would involve a horribly hacky method which is likely to be rather unstable. If someone can prove me wrong, I’d be delighted.

Secondly, transparent objects (models or brush entities) do not work properly. The only kind of transparency that will appear correctly is the colour-keyed pure blue ‘holes’ kind. Other types of transparency will not be rendered correctly – even additive sprites, which means that muzzle flashes on weapons do not appear correctly either.

Thirdly, you cannot use a large number of lights. This is true of all games that use bump mapping, so it is not a problem with this implementation. It is unwise to use more than three or four bump mapping lights in one map if you are aiming for playability on a GeForce 4.
</td></tr></table><div class='postcolor'>

Unless somebody can work around those issues I dont see it being practical in any mods any time soon...

Tequila · August 2004

Interesting, although the effect is rather ugly. Gotta admire the technical wizardy though.

CarNagE1 · August 2004

Yep its ugly. But it could look quiet good on some infested caves etc. <img src='http://www.unknownworlds.com/forums/html//emoticons/smile.gif' border='0' style='vertical-align:middle' alt='smile.gif' />

Soylent_green · August 2004

isch, useless. Lightmaps have no directional information. This would work ONLY for dynamic lights such as a special dynamic light entity, a flash light or welder.

Avitar · August 2004

As far as i am concerned this is a waste of time...

First i think it looks ugly...

Second instead of hacking the map up i rather just add more textures which render the effect that it produces.

KungFuSquirrel · August 2004

</div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><b>QUOTE</b> (Soylent green @ Aug 9 2004, 07:00 PM)</td></tr><tr><td id='QUOTE'> isch, useless. Lightmaps have no directional information. This would work ONLY for dynamic lights such as a special dynamic light entity, a flash light or welder.

Also, this is merely a tech demo shot without proper artwork. I guarantee the talented artists in the community could do some very impressive things with this.  </td></tr></table><div class='postcolor'> 
If you had read up on the feature, you would see that this actually adds a new type of light entity which behaves completely differently than the existing lights. Thus a map would have to be lit with this in mind from the start.

The_Real_Nem · August 2004

If you take the time to take a look at the pictures in the article side by side I think you will find that it looks a lot better (both more defined and more dimensional). The ceiling in the first picture is a bit misleading. The angle with the light and the ceiling is quite extreme it makes it look almost plastic, the other parts, however, look a lot better.

Unfortunately this technique looks like it would require dynamic shadows, which I guess is the next step. It doesn't fit well with the HL engine though. I've never done much coding with the HL engine, but does anyone know if it is possible to bypass HL’s BSP rendering engine completely and write your own? Doing so would allow you to optimize the renderer for this sort of thing and open up all sorts of worlds (shaders etc).

Nem

Chrono · August 2004

i still find it amazing that they are doing all this in such a old engine

BobTheJanitor · August 2004

Downloaded the provided minimod and ran around in the little test map. Never got a bit over 18 fps. And this is in a teeny test map, basically one room with some little details. System's athlon xp 1700, 768 mb ddr 266, radeon 9800se with softmod drivers. Nothing spectacular, but it can run most areas of doom 3 up near 60 fps (until monsters show up, of course <img src='http://www.unknownworlds.com/forums/html//emoticons/tounge.gif' border='0' style='vertical-align:middle' alt='tounge.gif' /> ) So I'm thinking this bumpmapping is mostly a proof of concept, not something that could ever be seriously implemented in a game, unless someone finds a way to do some serious optomizing.

Reese · August 2004

The problem is that, as far as i'm understanding it, this requires two additional rendering passes. Basically as you add things like bump mapping, shaders, possibly even masked textures, you require the video card to "go over" the screen again. The more times this has to happen to render a scene the longer it takes to do it. Basically these additional passes just add to what the video card has to do and will always impact framerate. All that combined with the fact that the half life engine wasn't built to use this (read as allow some cheating that will reduce passes, like current engines do) and the fact that it doesn't support brush based entities this is interesting, but not very useful.

Soylent_green · August 2004

</div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><b>QUOTE</b> </td></tr><tr><td id='QUOTE'> If you had read up on the feature</td></tr></table><div class='postcolor'>

I did read it and hence my common sensical and AFAIK accurate response.

</div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><b>QUOTE</b> </td></tr><tr><td id='QUOTE'>you would see that this actually adds a new type of light entity which behaves completely differently than the existing lights.</td></tr></table><div class='postcolor'>

Yes, I know, this is the "special dynamic light entity" I mention in my post.

</div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><b>QUOTE</b> </td></tr><tr><td id='QUOTE'>Thus a map would have to be lit with this in mind from the start.
</td></tr></table><div class='postcolor'>

Not possible to do on a larger scale, let me explain further.

It does add a new light entity, this is a DYNAMIC LIGHT essentially, like the flashlight or any other kind of dynamic light(which could also use this very same bump mapping technique as I mentioned). This is needed because you must have directional information, something the light map that half-life uses lacks.

It is VERY COSTLY to use everywhere, if you remade a map using this feature only you would have downright rotten performance and you could not use anywhere near as many light sources and every light would be a pointlight. This is not a problem with this particular implementation, this is allways the case, look at doom 3 or something, just 2-3 lights at a time, any more and it HURTS. This thing has no occlusion, this would, as was mentioned have to be coded for it to be usefull on anything but a tiny one room little test.

Bump mapping could be turned off to support cards that don't have shaders, but the light that must replace it(can't give people with better graphics card additional light sources can we?) would still be DYNAMIC and this hurts perfomance PLENTY and is not usefull at all for stationary lights. Doom 3 also has shadows, but if you turn them off, performance is still hurt ALOT by dynamic lights, it's inescapable.

Thus the only sane usage of this in half-life is as a special effect, used in conjunction with the light map, for lights that allready are dynamic(flash light, welder) or for light sources that shine at a very large angle from the normal of the surface.

It also adds LOTS of texture usage without making anything look nicer, breaks consistency cross machines unless you are carefull and code a simple replacement for those who cannot run the feature.

For this to be worthwile it needs to be used more than just once or twice in a map, to do this you have 2 options, you need to either do clever precomputation or you need to sacrifice all the players who cannot use this feature everywhere, neither seems like a workable idea. If you try precomputation you have big problems to overcome, you should keep the good old standard light maps for compatibillity with older machines, you would need normal maps for all textures, this is not nice work as considering the number of textures. You need transparency for mappers, e.g. modified compile tools that compute an extra light map that also includes directional information or something else clever. You need to elegantly solve the problem of how to combine many different lights shining onto a surface from different angles without using lots of seperate light maps for each and every light and without making omnidirectional/ambient lighting look like the harsh directional lighting of a point source and without making RAD take 10 times longer to complete. If there was a simple and elegant solution for this I bet it would have long since been implemented.

esuna · August 2004

That is so hideous. I mean really really really hideous. HL looks better without it imho.

Shoot_me · August 2004

Meh, it'd be nice if someone could figure out a painless way to add bump maps to HL, but with HL2 around the corner (maybe), and Doom3 already out, why bother? It’d be best to use a game engine that is optimized from day one to use these extra features than to keep tacking this stuff onto the old HL engine (reminds me of one of the Dell commercials).

That, and being forced to compile two different types of lighting schemes (for compatibility) would just be one huge headache. It's hard enough getting the lighting just right as is.

I just opt to have HL keep it's "dated" look. Besides, I like the way mods like NS look on the HL engine as they are right now.

Ripzaw · August 2004

Well each texture has to be coded for this to work. It's like if you make a wall to be real instead of having to put each brick in and then filling the bits in between a little futher back for the cement this just has 1 wall with 1 texture and make the effect of inlays etc. Clever effect really <img src='http://www.unknownworlds.com/forums/html//emoticons/smile.gif' border='0' style='vertical-align:middle' alt='smile.gif' />

TGRanger · August 2004

It may well be clever that someone has done this, but it doesn't look right in half-life. I dont see the point in trying to add special efects to half-life when you can just wait for half-life 2 or any other new game that can do much much more without terrible framerates

TheChuckster · August 2004

Seems like a messy "hack" to me, even moreso than detail texturing. <img src='http://www.unknownworlds.com/forums/html//emoticons/confused.gif' border='0' style='vertical-align:middle' alt='confused.gif' /> If we want better graphics then time to use a new engine.

Reese · August 2004

In addition to what Shoot me has said I'd like to add something else.

One thing I love about mapping for NS is the ability to use tons of light sources. If I feel like making a room that uses nothing both one of those 32x16 lights, but uses it about thirty times, I can. From the engine's point of view it makes no difference as these are all static lights, and that's the only kind of light the engine supports. (Saving entirely precompiled light information to the bsp doesn't count as dynamic lighting IMO) Anyways, trying to do the same thing in doom 3 would bring any current system to it's knees. The point here is that there are advantages inherent in the limitations imposed by the half life engine. People still use bicycles even though we have cars.... sometimes a bike is just what you need to get the job done.

The_Real_Nem · August 2004

I think people are mistaking this for some intensive new technology that only the latest and greatest hardware can handle. It is not. Dot3 Bump Mapping and Dynamic shadows have been around for years and are supported by all current hardware and most hardware made over the last four years. The same can be said for multiple texture units (and all you would really need is two texture units which is a very modest requirement).

To render a level with bump mapping would require a pass per light, but the number of actual lights would be rather limited. Really you only need a pass per face that the light can see and we already have the perfect system built right into HL1 which can determine which faces are potentially visible, the VIS (you could even use backface culling to cull additional faces from the light's position). Once you have the faces the light can see you can further reduce the faces that actually need to be rendered by removing those that aren't visible by the camera. You might end up with 1000 faces that the camera can see plus 500 faces (on average) that each light can see times 20 lights (on average) that actually touch any visible face; so you'd have 11,000 faces total to render. After some optimizations this number of faces is peanuts to any decent graphics card.

Adding dynamic shadows would be a fair bit more complex but certainly conceivable. You could also use lightmaps for the shadows. All the above would require overriding HL's BSP rendering engine.

Nem

Bump Mapping

Comments