Question about normal mapping & textures

[Gaelion]

Hi,

I'm completely lost with normal mapping when it comes to texturing the model.

Does the normal mapping contain the texture of the hipoly model as well, or should I make a different texture for the lowpoly model?

If I have to make a texture for the lowpoly model, should I make it before or after applying the normal map?

Ive gone through the tutorial listed in the forums, as well as through many posts about normal mapping, but I can't figure this out.
I guess it must be something really obvious but I'm completely stucked  

I would really appreciate an explanation about this.

Thanks a lot

Gaelion

[potato]

A normal mapped model you would see in a game like Doom 3 consists of 3 maps:

- Diffuse map
- Normal map
- Specular map

The diffuse map is your "color" texture. The normal map is what you generate from your hi-poly model, and contains all the lighting information (among other things) you need to render your model. The specular map defines the shininess of each part.

I'm not understanding your question about "does the normal mapping contain the texture of the hipoly model". Normal mapping generates the normal map, all the other maps are YOUR responsibility. A normal map is simply a texture that contains the normal vector of your model at every pixel, it doesn't include anything else.

That said, what you should probably do is make your diffuse and specular textures for your hi-poly mesh, and use them for your low-poly one as well. After all, normal mapping is designed to make a low-poly mesh look just like the hi-poly one.

[Gaelion]

Thanks a lot for the reply!
I think I now understand better waht is it about. Could you please confirm this?

If I understood well then this is what I should do:

Create Hipoly model plus its texture map (diffuse map)

Create Lowpoly model

Generate normal map

Use LowPoly model+normal map+ same texture map as the hipoly model

and then the lowpoly model should look quite similar to the hipoly model?

Thanks again

[potato]

That's right. For many engines, including TV6.5, you can also include a specular map that defines the object's shininess at various parts.

The diffuse map for a normal-mapped model is different from traditional textures that we've been used to making up till now. We're very used to burning lighting into these textures, but with a normal-mapped model's diffuse texture it's important to make sure you're not including much lighting, if at all. It should be perfectly flat - let the engine handle the lighting.

[Gaelion]

Great! Finally understood!

Thank you so much for the clear explanation & quick help!