Texture creation theory
This article is meant to explain the theory behind creating custom textures for your maps. I'm not going to discuss any techniques to achieve certain effects, after all this is not a tutorial, but I’ll try to give you a step by step guide of what you should do to get nice textures in your maps.
Every level designer faces the same problem at some stage of his/her work, which is not having the right texture for what is required. This is where custom textures come in, besides giving more possibilities to the designer; it also increases its quality and value, since custom textures show that you actually put some effort on your creation. The trend nowadays is to use photo based textures, which are textures that use a photo as a base, and then are hand edited in image editing programs to achieve a better effect. So since we are talking about photos, the first thing you will need is a camera.
1 - The Camera
I'm not really an expert in cameras, but I’ll try to give you some advice on what to buy. First of all buying a camera just to use for textures is a bad deal, make sure it will fit other purposes, or that you don't buy something too expensive. Of course when we talk about cameras we are talking about digital cameras, since they are easier to use, and give a better and faster result. You don't need a camera with lots of mega pixels, since probably the maximum picture size you will need is 1024x1024, so I think that a 3 mega pixel camera works really well here.
2 - Searching The Web
Many of you may not have the money to buy a camera, but in the internet era there is always a solution for every problem, and luckily there are sites that have lots of pictures for you to use. The most known is Google image search, but to get good results here there are some things you need to be careful with.
First of all you need to have a clear mental picture of what you want, and have your map theme well defined. Having this you need to turn those images in your head into keywords, for example "brick wall" "metal floor", this usually gives some nice results, and if you’re lucky you may get some textures made by other designers also. Another thing you should be careful with is the size, if you look in the top right corner you will see something like "show: All sizes - Large - Medium - Small", always filter your search using either large or medium pictures, because a small picture is not very useful. I'll leave you now with some links to websites with hundreds of nice pictures for you to use, that where mentioned earlier in a tutorial:
3 - Choosing The Right Picture
The next thing you should learn is what pictures to use. For those of you that are using a digital camera here is what you need to have in mind while taking your pictures.
Assuming you already have the theme of your map established it is time for you to look around your city for places that resemble what you want to map.
Always choose rainy/overcast days to take pictures, unless you’re going for a very sunny map style. The thing with rainy/overcast days is that it enhances the details on the surfaces, plus it gives you some water marks, and cleans it a bit more. Also you won't have to worry about sun reflections or any light problems, making the image easier to work on.
Now while taking the picture make sure you are placed in a position perpendicular to the wall, this will avoid having to mess with the perspective and distortion, and don't forget to keep your h ands still, or it will get blurry. First thing to do now is to take a global view picture of the area, this will give you some ideas for your brush work, and will allow you to remember later where the picture was taken, in case you want to go back and take some more. After doing this start shooting closer, look for some nice and clean pieces of the chosen area, that don't have many outstanding details, since that would make it harder to tile later. Make sure also that there aren't many lights/shadows cast on the surface, and are fairly uniform.
After getting some good base "textures" you can take some shots of details like windows, doors, vents, etc.
For those of you that don't have a camera, you should still use the same principles while selecting a picture, although your job will be a bit harder since you will have to do lot's of editing later. Talking about editing...
4 - Editing The Photos
First thing is to choose which software your going to use, the must well known are Photoshop, Paintshop, and The Gimp, but if you ask me there is only one good photo editing software and that is Photoshop.
Now open up our pictures, and crop a good section of it, one that is really clean (Doesn't have many lights or shadows or big details, but it can still be a dirty or old surface), and that should have two times the size of your final texture, which should be 4 times the size of the brush your using it on (if you have a 128x128 brush you need a 512x512 texture and should crop a 1024x1024 section from the picture). This will be the base of our texture, so you should work on it first. Until you finish up your texture never, ever, EVER, resize it, since it will loose quality and look really bad at the end.
Now you have the base what should you do with it? Start with fixing the perspective and distortion on the picture, depending on the software your using there might be different tools for this. Then fix any light or shadows on it. Now you need to make your texture tile properly to be used in game, there is already a tutorial on this so just to give a quick explanation. First offset the texture by half its width and height, and then using for example the clone stamp and heal brush tools (from Photoshop) clean up your seams, and erase any artefacts that the texture may contain. Now you should have a clean and ready to use in game texture, just need to save it in the appropriate format.
But you shouldn't stop here, after having the base, it’s time to work on the detail, and make some variations of the texture, like adding windows, doors, vents, different colours, etc. This is where the artist imagination and skill come in, you can overlay other photos, hand draw some details, use filters, everything you can think of, and that would make your texture better. Don't forget to never leave your texture crystal clean, it should have some randomness, and show some scratches, paintings, water marks, rust, etc. Nothing is perfect in the real world and you should never forget that.
5 - Finishing Up
Now when you think your texture is ready is time to give the final touches.
Make sure that your textures look nice next to each other, and that they don't have extreme colour, brightness and saturation differences from the rest of the textures.
Its now time to sharpen and resize so first you should resize your texture to 150% of the final size, which is 75% of the current size (say for example the final size is 512, and your working with 1024, you should resize to 768(512+256)), after doing this run a sharpen filter, then resize to the final size (512 in this example) and run another sharpen filter. Now go on and test your texture, and make sure everything ended up has you wanted, if not it's a good idea to have several editable files (.psd files in Photoshop), from different stages of the creation of your texture, so that you can change everything you want without having to start from the beginning.
By Barrakid 03/06/05