Tutorial: Detailed Textures in Half-Life Last edited 3 months ago2024-09-20 11:10:49 UTC

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Thanks to an update from Valve, version 1.1.2.0 for the GoldSource engine now includes detail texture support. Some people may be familiar with these very powerful visual effects but this tutorial not only demonstrates how to implement them into your map but also some very good looking tweaks for advanced users. Keep in mind that you need the Steam version of Half-Life to use these as Valve stopped updating WON versions long ago.

Creating a Detailed Texture

First up, what is a detail texture? A detail texture is a high resolution external image (TGA image file) that is placed over the top of a map texture. This gives the impression of a small details when you get up close to a texture instead of the usual blurred image you get when the texture fills the screen.

Now you will need to create a detail texture to use in your map. I use Corel Photopaint 10 but any other graphics programs that can create TGA images are suitable. The ideal size for a detail texture is 128x128 pixels. The recommended maximum size is 256x256 pixels because although they can be larger, results can become unpredictable. Detail textures are best made with the grayscale pallet, in other words, don't use colour. When creating your image remember that the colour 128 128 128 on the RGB (red, green, blue) scale will be completely transparent. Brighter shades create highlights and darker shades create shadows. To avoid blotchy and ugly looking detail textures, always try to remain close to the middle gray colour when making shadows and highlights, as very white and very black shades will cover the map texture and look more like paint on your map texture. Once you create your image, save it as a 24-bit colour, uncompressed TGA image in the directory: Half-Life/(modname)/gfx/detail/mytexture.tga. You can create a subdirectory within the detail folder but for now this will do.

Implementing Detailed Textures

Now that we have a detail texture, we can use it in our map. Go to your half-life/(modname)/maps folder and create a new TXT file the EXACT same name as your map name but add the prefix _detail.txt to the end. Eg, bigbox.bsp, bigbox_detail.txt. Open up the TXT file and add the following line:

texname detail/mytexture 2.0 2.0

The first value is the name of the map texture to apply the detail texture to, you need to rename this to the name of the texture you used in your map, eg, if you used the texture C1A0_LABW2 in your map you need to replace texname with C1A0_LABW2, it is not case sensitive.

The next value is the directory and file name of your detail texture you just created. The engine will only look in the GFX folder and the file extension is not required as it is looking for a TGA file. The advantage of this is that you can have a subdirectoy to use for your own map, eg detail/bigbox/mytexture.tga, and you won't overwrite other map's files if they have the same name.

Next two values are the scale. This is the number of times your detail texture will tile compared to the size of the texture. The first is the horizontal scale and the second is the vertical scale. So if the texture in your map is 256x256 and you set the scale to 1.0 and 1.0 then it will tile once in that 256x256 sized texture. This means, however, if your detail texture is 128x128 then it will stretch to fit, decreasing its resolution. If the map texture 256x128, then again, it will be stretched horizontally to fit, making it look bad. The larger the scale you set, the smaller your detail texture gets and the resolution is increased, but it can lead to an unappealing 'repeating' look if you tile, say, 10 times. Just to further clarify, if you used a 64x64 detail texture on a 128x128 map texture, you would probably want a scale of 2.0 and 2.0 so that it is not stretched to fit, instead repeating 4 times in that 128x128 map texture. Remember that these numbers do not mean to scale up making it twice the size, they mean how many times a detail texture will tile in a single map texture. These scales also take into account the scale of the map texture set in Hammer (or Worldcraft) so that they always match. If you stretch your map texture, the detail texture does the same.

You need to repeat the process with every texture in your map that you want it to apply to. This can mean a long tedious process but the rewards are well worth it. You can also use different detail textures on different map textures. Want a tile effect on your floor tiles? What about a rough rock look on your rock faces? Just change what detail texture to use on each surface. Eg,

rock detail/myrocktexture 2.0 2.0
floortiles detail/mytiletexture 2.0 2.0

There is no known limit to how many detail textures you can use at once and you can have as many entries as in the _detail.txt file as you want. Now save the file and load your map in Half-Life. Make sure the cvar r_detailtextures is set to 1 and you should see the detail texture on every texture that is defined _detail.txt file. The good thing about detail textures is that you do not need to recompile a map if the detail texture loooks wrong, it is done in real-time. Make changes to the _detail.txt that you want and reload the map. Half-Life re-loads the detail textures used every time a map loads.

Keep in mind

Using detailed textures also has a massive impact on the quality of your map's lighting if used correctly. Because of the difference between light and dark shades and how they create highlights and shadows, you can use this to simulate, more appropriately, the material surface. For example, metal reflects much more light than concrete and therefore, looks brighter than concrete, even if the two materials are right next to each other in the same lighting conditions. Normally, Half-Life cannot discern between different materials like the Source Engine can but clever use of detailed textures can help simulate these conditions. By making metal detail textures brighter than normal, you 'lighten' the the map texture, because brightness values are also overlayed by detailed textures. Again, apply a darker detailed texture to a dark concrete surface. Now, when the map is lit, the metal looks brighter than the concrete, which is much more realistic.

Advanced Features

Now, after a bit of experimenting, you can manipulate the power of detail textures for greater purposes. One use is for a cool sand effect. Want to have a nice glowing effect for your sand and improve its appearance? Create a full colour sand texture and use it as a detail texture over your sand map texture. This goes for all detail textures, they do not have to be grayscale images, colour detail textures will also overlay their colour properties to the textures and because detail textures are not heavily reliant on lighting for their appearance, unlike normal map textures, they can create a glowing effect. This is not applicable for all uses, however, use at your own discretion.

Using a rough looking map texture? Extract the texture from the wad and convert it to a grayscale detail texture and use a scale of 1.0 and 1.0 in your _detail.txt file. This will greatly improve the look of the map texture by adding a small amount of depth and highlight to your map texture.

Detail textures can be applied to solid colour transparent textures, ie, map textures with the { prefix. The engine will automatically render the detail on the visible parts of the texture and not over the transparent colour. This does not, however, apply to normal transpartent textures like glass or any other texture that has the rendermode set to 'texture'. The engine can't overlay a transparent texture over a transparent texture so it does not work.

Remember! The Steam version of Half-Life is required! This will not work on older WON versions!

I would like to thank the following sources for support and detail textures to experiment with:

VERC
Ragnarok Arena (for packing a whole bunch of borrowed detail textures)
TWHL