For modders. Tips for optimization of DDS textures

[Zorba]

Diffuse texture - if it doesn't have transparent and translucent elements, you can safely save them in DXT1 format. This will save the memory of the computer, especially when these textures a lot. If you have transparent parts, then DXT5.

The Normal map - should not be a lower resolution than the Diffuse, it greatly affects the overall quality of the display in the game. Always save in DXT5 format (For modders, you can save in high quality uncompressed A8R8G8B8 or TGA).

Specular maps - does not have an alpha channel, you can always save in DXT1 format, (there is no need to save them in DXT5 format), and if you have only one solid color, it is possible to keep the resolution smaller than the Diffuse texture, reducing the resolution of the textures, does not affect image quality, but reduces the load on the graphics card.

I hope this information will be useful to someone.

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Для моддеров. Советы по оптимизации DDS текстур:

Diffuse текстура - если она не имеет прозрачных и полупрозрачных элементов, то можете смело сохранять их в формате DXT1. Это позволит сэкономить видеопамять компьютера, особенно заметно, когда таких текстур много. Если есть прозрачные детали, тогда DXT5.

Карта нормалей - не должна быть разрешением ниже, чем Diffuse, это сильно сказывается на общем качестве отображения в игре. Всегда сохранять в формате DXT5 (Для моддеров можно сохранять в высоком несжатом качестве A8R8G8B8 или TGA).

Карты отражений - не имеют альфа канала, можно всегда сохранять в формате DXT1, (нет никакой необходимости сохранять их формате DXT5), а если имеют всего один сплошной цвет, то можно сохранять в разрешении меньшем, чем Diffuse текстура, снижение разрешения таких текстур, никак не влияет на качество картинки, но уменьшает нагрузку на видеокарту.

Надеюсь, эта информация будет кому-нибудь полезна.

[simplesim7]

Good to know, thanks. I'm not proficient in texturing, this helps alot.

[antales]

Please mind that we are not using RGB format for normal maps. Instead we are converting them to RRRG and saving as DXT5. DXT5 splits color and alpha so there is no blocking of data. In shader RRRG converted back to RGB (B is restored as normal is always 1.0 length).

[Zorba]

antales,
Спасибо за пояснения.

[simplesim7]

Originally posted by Svetoslav:

antales,
Спасибо за пояснения.

Can you teach me how to correctly use colors on the specular map?
What color for glossy, what color for semi glossy and what color for non gloss?

Also how do I generat normal maps?

I'm not good at texturing.

[antales]

We use roughness + intensity specular model. R channel is roughness, G is intensity, B is unused (set to zero).

The lower the Rougnhess the glossier the surface. Roughness of 1.0 (255 in byte version) is for non gloss. Do not recommend to set Roughness to zero. Just close enough.

At current generation normal maps are generated by baking high detail geometry onto low detail.

[Zorba]

A normal map - is a texture in the color channels where the saved vector offset information point hi-poly model over the low-poly model.
The red channel defines the horizontal (X coordinates) vector. The green channel defines the vertical (Y-axis) vector. The blue channel determines the height (axis) of the vector, all values up to 128 means that the surface is not visible (or rather twisted in the other direction) and it is not a dynamic light. Therefore, these values are not used and texture to the normal purple color.

Normal maps can be created in 3dsmax, also there are plugins for photoshop and paint net. Are there other programs that can do it in the likeness of CrazyBump.

(Specular map – texture that shows the ability of the reflecting material. Shows the reflection of light falling on it. A specular map contains the pixels in the black-and-white color scheme. The lighter the pixel, the greater the ability of a material to repel light and the brighter it glare from the light. Accordingly, the darker the pixel, the v becomes material and loses its ability to reflect light. Materials For ceramic tile and polished metal can be used bright colours and fabrics and wood - dark.

But I see this game uses colored specular maps.
In this game, as said antales, the blue channel is not used.

A texture that controls the intensity/color of the specular highlights from real-time lights.
Usually a specular map simply controls the brightness of the highlights, at a per-pixel level. If the shader supports RGB the specular map can be used to colorize specular highlights, useful for surfaces that have more complex reflective properties like metals, beetle shells, etc.
Sometimes a shader will also support per-pixel control for the width or power of the specular highlights, this is often called the Specular gloss map.)

Amendment.
Obsolete. The game uses a different, more advanced rendering method.

Maybe you will help
Normal map[wiki.polycount.com]
Tool[cpetry.github.io]

[antales]

Not exactly :)
Specular Maps as you described were used in euristic lighting midels like Phong or Blinn. Today they are obsolete. Now we use Physics Based Rendering (PBR). Common model is a Cook-Torrance microfacet approximation model with Roughness. Roughness describes a reflection distribution. Roughness of zero (polished surfaces) corresponds to mirror. Roughness of 1.0 (255) corresponds to non-gloss surfaces. Roughness is a scalar parameter so we need only one texture channel - we use Red. Brighntess (or Intensity) of the reflected light stored in Green. PBR approximations do not use Intensity as a parameter, but we use for artistic purposes. In most cases you want this parameter to be 1.0 (255)/

[Zorba]

Thanks for the info, I never heard about this technology before. It does look more realistic.

[simplesim7]

Appreciate the info from both of you ;)

[𐂃𐂃]

Ok, I am not dds format expert. And I have troubles saving normalmap in proper format for this game. I tried Gimp plugin, tried Paint.Net, and Crazybump and I always end with gray quads or someting like that. Can anybody help me please?

here is how it looks: http://i.imgur.com/J6PRch6.png

[simplesim7]

Originally posted by DaXmAn:

Ok, I am not dds format expert. And I have troubles saving normalmap in proper format for this game. I tried Gimp plugin, tried Paint.Net, and Crazybump and I always end with gray quads or someting like that. Can anybody help me please?

here is how it looks: http://i.imgur.com/J6PRch6.png

Download this pluginfor paint.net, normalmapplus
https://drive.google.com/file/d/0B3gGHvIrj_sWOXNheXhqS3FNUlk/view?usp=sharing

Under effects\stylize NormalMapPlus

[antales]

Originally posted by antales:

Please mind that we are not using RGB format for normal maps. Instead we are converting them to RRRG and saving as DXT5. DXT5 splits color and alpha so there is no blocking of data. In shader RRRG converted back to RGB (B is restored as normal is always 1.0 length).

The resulting image is gray.

[Zorba]

I honestly don't understand how to convert normal map in RGB to format is RRRG. I just make it translucent, the game looks good. But if you leave an opaque RGB, specular map not working.

[𐂃𐂃]

@antales: I read your post antales, but honestly I have no idea how to convert image to RRRG, in all those tools I mentioned I just can save in DXT5 format, there is no option to change format or whaterver it is ;) any suggestions?

@simplesim7: yeah, and what about plugin? I put it into paint.net/Effects folder, and in Paint.Net I can just alter normalmap, but the way normalmap is saved is still the same.

[antales]

You need to work with RGB channels. Select G channel and copy it to Alpha. Then select R channel and copy it to G and B. Then save to DXT5.