Can you normal map this?

[Vulture117]

Hey guys

Well you know how there are blood splats on models (eg. all source games) i was wonderin is it posible to make normal maps like that so when shot it will give the ilusion of being blown apart?

Im asking this because I am working on a model of an arachnid (from starship troopers) and i want to try and get it ingame and it would make it all the more authentic if it got totaly messed up when it gets blasted at.

Here are some pics

http://img361.imageshack.us/img361/9613/bug61gy.jpg

http://img361.imageshack.us/img361/4338/bug59im.jpg

http://img361.imageshack.us/img361/3071/bug46zl.jpg

The first one has a polycount reading on it so give me some feedback if my models ok or not and if the polies are too high.

Thanks

 

[mikeandike22]

polies seem pretty high for a model like that it looks like some of the features that a bug would have like eyes are missing, mb they are there i really cant tell cuz u cant really render for the hl2 xsi mod tool w/e.

 

[Ti133700N]

Normal maps:
I've never seen any normal mapped decals and it would be kind of wierd to normal map decals since it's like a texture applied over another texture and therefore cannot modify the normals of the actual model. I don't know if they managed to code something that would know what normal to modify even if the texture is applied over another texture. Imagine if the base texture is normal mapped, how can a normal mapped decal could modify the already modified normals of the normal mapped model... Duh lol!

Polycount:
If your goal is to make a map or a MOD with alot of arachnids, then yes the polycount is a little high. If you don't plan to put more than 7-8 arachnids on the screen then it's ok.

 

[Shinobi]

the decal could just have priority and override the normals of the model

I can imagine that actually being useful for something like a large bullet hold on a mech/robot

 

[mindless_moder]

i was under the impression that hl2 did this ...how else does it manage to make dents on barrels ? if it uses a bump map i dont see why it cant use a normal map ....but thats besides the point i think what hes talking about is Gibbing.

 

[Ti133700N]

If the decal would have priority over the normals of the base texture, the model would suddenly look flat as soon as it would get shot (exept the decal part (wich is small)), that wouldn't look good. The decals used for gun holes are like bump maps, that's why they look good. They have been programmed to be used this way so I doubt they can be normal mapped.

 

[Vulture117]

lol thanks

Thats funny i got the impression that a bump map and a normalmap were the same thing.

Also about the poly count I know im not going to be able to get a million of these things on the screen and also if i start sacrificing eny more polies it will start to not look very good.

Also ive noticed that in the f.e.a.r. demo they seem to have normal maped decals on the walls and the walls seem to be normal maped so i dono.

 

[Shinobi]

If the decal would have priority over the normals of the base texture, the model would suddenly look flat as soon as it would get shot (exept the decal part (wich is small)), that wouldn't look good. The decals used for gun holes are like bump maps, that's why they look good. They have been programmed to be used this way so I doubt they can be normal mapped.

I meant the only normals that are overridden are the ones from the decal, use the alpha channel to calculate it,, I dont mean cancel the underlying normal map,,

 

[mindless_moder]

their walls are probably bump mapped not normal mapped. i doubt that anyone would ever normal map walls unless it was smething rocky like in the hl2 wall video.

 

[Ti133700N]

I meant the only normals that are overridden are the ones from the decal, use the alpha channel to calculate it,, I dont mean cancel the underlying normal map,,

Ok that's a solution, but I think the common way of doing this is to blend the normal maps before the lightning pass. An engine could also use heightmaps, so parralax mapping. I don't know if F.E.A.R uses bump mapped or normal mapped or parralax mapped decals, but i'm pretty sure Source can't support anything else than bump maps for decals. With the powerfull pixel shaders, you could code an engine so that it would use parralax mapped decals (I'm pretty sure that will be the case for Unreal Engine 3).

 

[thereisaspoon]

bump maps dont exist in hl2, the grayscale one.
everything is a full normal map, so if you make a decale with a normal map it will simply apply it on the model, it dosent cancel out the model normal map since the bullet hole is a different entity. The metal bullet holes for example use a normal map.

 

[Shinobi]

bump maps dont exist in hl2, the grayscale one.
everything is a full normal map, so if you make a decale with a normal map it will simply apply it on the model, it dosent cancel out the model normal map since the bullet hole is a different entity. The metal bullet holes for example use a normal map.

you can parallax map in HL2 (from grayscale maps) here's how:

http://developer.valvesoftware.com/wiki/Creating_Parallax_Maps

 

[Ti133700N]

bump maps dont exist in hl2, the grayscale one.
everything is a full normal map, so if you make a decale with a normal map it will simply apply it on the model, it dosent cancel out the model normal map since the bullet hole is a different entity. The metal bullet holes for example use a normal map.

Hum... ok so how do you explain that the "metal bullet holes", to use your example, are grayscale?

you can parallax map in HL2 (from grayscale maps) here's how:
http://developer.valvesoftware.com/w..._Parallax_Maps

That's kind of interesting but like it's written at the beggining of the tutorial :
"WARNING: The parallax mapping feature is currently unavailable in the Source / Half-Life 2 Engine. While it will not cause issues if implemented, you will not notice any results."

So, i'm still not convinced that you can currently normal map or parralax map decals with the Source engine.

 

[Shinobi]

dammit, I didnt even read that part,, well I'm an idiot

 

[Vulture117]

*eye twitches*

Well i thought i new this stuff but I was obvously wrong. Just wonderin isn bump map, normal map, displacement map and parralax map all synonyms for the same thing?

 

[FictiousWill]

If you want to do it right you can - but you'll need to do a small amount of very clever coding and have a very complicated model, with each part you want to be blown off being a separate attachment that is separated from its parent when hit.

What I would do is make the head a separate piece from the body. Make it an attachment on the center of the leg base. Add a check for a hitscan on a hitbox around that central area and the player is rewarded with a decapitation for a well placed shot.

Keep it low poly. Ultra low poly. Unless you're willing to model different versions and mip the sickers at ten feet or something. If you can't have a million of them on the screen at one point then there's no real point in having them. They're bugs for goodness sake - that's what they do.


edit: bump, normal, displacement, height, spec, alpha, and parallax maps are all completely different from each other and are used for very separate effects.

 

[Vulture117]

thanks ill look all this stuff up then.

And my model just so you know Is my third ever so I still am geting the hang of it. Also ive thought about doing that and if i were to do that ide only do it on the do the joints of the arms, legs and beak and do the abdomen because thats were in the movie the bugs realy get the shit blown out the back if you know what i mean.

 

[Shinobi]

*eye twitches*

Well i thought i new this stuff but I was obvously wrong. Just wonderin isn bump map, normal map, displacement map and parralax map all synonyms for the same thing?

well they all have a similar goal for results,, to fake depth and geometry complexity, they all just have different ways of going about it...

bump map: height depth fake
normal map: face normal & depth fake
displacement map: actual depth change (so not really used in games because of this)
parallax map:new crazy height illusion map, not too sure how this one works
relief map: even crazier new height illusion map, someone got this working in doom3, looks crazy

 

[Vulture117]

Thanks that helps alot, thats proly why i thought they were the same thing cause they all do similar jobs. For that doom3 thing can you post a link ide like to see.

Cheers :cheers:

 

[Shinobi]

here you go

http://www.inf.ufrgs.br/~oliveira/RTM.html

scroll down to the bottom to see movies of it working in doom3 as well as compatison to a regular normal map

 

[Vulture117]

thanks

WOUH THATS FREAKEN AWSOME!! 8D