Engine level normal map support

[Beherith]

So, after much hand wringing, I decided to try implementing engine-level normal map support. This includes the following:

• Bump maps on features
  Bump maps on units with no lua unit shaders overhead (in my experience, the overhead there is massive, nearly 50% less fps when many (100+) units are on screen
  Bump maps for units under construction

It was surprisingly easy to do in a hacky way, but there are a few caveats that should be discussed.

1. Where to store the normal map/unit assignments?
Currently, i hard coded to load a texture that is called the same as texture1 (e.g. Arm1.dds -> Arm1_normal.dds)

Code: Select all

		
S3DModel* CS3OParser::Load(const std::string& name)
...
model->tex3 = (char*) &fileBuf[header.texture1];
model->tex3 = model->tex3.insert( model->tex3.find_last_of("."), "_normal"); //horrible hacks by beherith
...

Since adding a third texture to the s3o format seems very complex, and defining it elsewhere is difficult to get the right balance of simplicity/configurability.
I figured that normal maps are nearly 100% tied to the diffuse texture1, this would be an 'ok', if hackish solution.

Also, if a normal map cannot be loaded, this allocates a single pixel dummy normal map. Which brings me to my next point

2. Texture caching.

I did a horrible hack to change the 'hash' function:
from
#define TEX_MAT_UID(pTxID, sTxID) ((boost::uint64_t(pTxID) << 32u) | boost::uint64_t(sTxID))

to:
#define TEX_MAT_UID(pTxID, sTxID, tTxID) ((boost::uint64_t(pTxID) << 32u) | (boost::uint64_t(sTxID) << 16u ) | tTxID))

As I saw that texID's seem to be small values, incrementally assigned, and the chance of a collision seemed very low.

Just a screenshot of features and units having engine-level normal maps:

screen00066.jpg

(1.07 MiB) Downloaded 2 times

Any thoughts are welcome

[gajop]

Needs a comparison screenshot. I think I can see the effect in the tires and the blue parts of the robot but it's not super obvious.
Also good for separating it from S30. Any reason it couldn't be used for assimp too? Seems fairly obvious.

[Beherith]

Vanilla:



Engine normals:



Keep in mind that the normals on the wreck and the tree were just button mashed quick generated with nvidia photoshop plugin.

[smoth]

Not bad behe!

[Silentwings]

Can't see the difference on the unit, but the wreck looks great.

[PicassoCT]

Dat ground



Makes me sad panda for knowing that this is too much work for a one man project.
Allready have to redo the gui.



If spring had bump generatinon as a graphics option..
https://github.com/kmkolasinski/AwesomeBump
but then still ..

[gajop]

While the effect is more obvious on the feature, the feature itself is weird with some texture seams in the original and the final is random so it's hard to tell what's desired.
The unit feels much "sharper" which is probably one of the desired effects so +1

PS: I realize I have great difficulty telling whether normal maps are being used or not.

[smoth]

it's probably that in in 0ad they have translucency support and we do not. that causes what appears to be "seams" if you are talking about the yellowish edge on the leaves.

[Super Mario]

Can you write an actual function equivalent to the #define by expanding it, to make sure that the compiler catches any bugs? I remember a certain bug, that prevents msvc compiler support.

[Beherith]

Dat ground

Makes me sad panda for knowing that this is too much work for a one man project.
Allready have to redo the gui.



If spring had bump generatinon as a graphics option..
https://github.com/kmkolasinski/AwesomeBump
but then still ..

I knew you would notice the crystals, Picasso :D (the secret is that terrain is also bump mapped now :O )

Also, super thanks for the awesomebump tip, it is a very powerful free and open source bump map creator.

Screenie:

[PicassoCT]

okay fuck all reason i need to have this

[code_man]

Very nice, i sure hope this will be in the engine.

Spring is a great engine, but it fell behind over the years i fell.
Even zero hour has bloom and bumpmaps hacked into it nowadays.
Im not one of these people who get a hardon for gfx, but i sure wouldnt mind a bit more shiny stuff, im sure many would like that too.
Would be nice if we get a bit of bloom in the future too.

[smoth]

very cool behe! I also didn't realize people liked my distillery

[Silentwings]

Would be great to get this into the engine...

For 1, I guess filename in unitdef file and a normals dir in the base game dir.

[Beherith]

Well, since it's not limited to units, and works on features and projectiles too, adding it to definitions is a tad iffy.

I cant think of a reason besides code cleanliness to not load them with the models themselves.

Oh and btw, it costs nearly 0 performance :)

[FLOZi]

Well, since it's not limited to units, and works on features and projectiles too, adding it to definitions is a tad iffy.

I don't see how, don't they all inherit from WorldObject? That's where model is. Or am I not following you?

[Silentwings]

Features can have defs too - https://springrts.com/wiki/Gamedev:FeatureDefs - but projectiles (afaik) don't, the models used are just identified in the weapondefs by filename.

[Kloot]

Quick opinion:

Normal-mapping on the engine side is trivial, but would mostly be limited to games that don't employ custom shaders at all or only for NM. On the other hand the default shaders could be made to support a wider range of standard bling with not too much work, and cover most of the custom cases. Just having mapped normals on props isn't enough of a draw.

Normal-map generation really belongs in an artist pipeline, not the engine.

[smoth]

Shaders cannot be assigned to features.

[Silentwings]

Normal-map generation really belongs in an artist pipeline, not the engine.

I'm confused by this - I thought that was what going in Behe's code was that the generation of normals was getting done by the artist alongside making the model, and its the rendering based on the normals that's being done inside the engine. Are you saying that ideally all non-basic rendering should be done, by the artist, in a (lua) shader?