The point of this series of articles is not to provide any pointless step-by-step instructions for creating textures, because in the end those don’t really teach very much at all, and instead of actually teaching concepts, all they tend to do is demonstrate a single approach to a specific situation, often leaving the artist with little knowledge about how to tackle a variety of texturing issues that he or she is bound to face on a regular basis. Instead, this article simply discusses the theory behind texture painting, thus enabling you, the artist, to understand why and how this process works, so you’ll be properly prepared to handle texturing tasks on your own in the future.
A short note on terminology
It is worth spending a mooment here at the beginning to discuss the difference between a shader and a texture map. Despite the important relationship between shaders and textures, this article is not about shaders as such, but rather about the mappable components of shaders, like colour, specular and bump maps. Roughly speaking, a shader defines the way in which light interacts with the rendered 3D surface, thus determining the actual quality and substance of it, whereas textures add details that the shader alone cannot. Understanding how the different properties of a shader works enables you to successfully create textures for each of these components, in order to create realistic and effective materials for your 3D models.
Looking at the world a little differently
As a texture painter, it is vital to be able to observe the world around you in such a way as to enable you to understand exactly what you need to create within the computer generated environment in which you work. Merely observing the world on a superficial level is not sufficient.
Take a look around you. What do you see? Naturally you see the world that you have been looking at every single day of your life. Now take another look. This time, concentrate on every different surface that you see, and describe to yourself exactly what the surface looks like. When you begin to describe what you see, you’ll notice that every surface is comprised of many different qualities. Concentrate on one particular surface near you. What colours are in the surface? Look for uneven tones or grit that may create variations. Are there any scratches, fingerprints, or other blemishes or imperfections in it? Is it reflective? Does light penetrate it at all? Questions like these help you to understand exactly what you need to create in order to recreate the surface.
Touch the surface. Is it hot or cold? Smooth or rough? The actual tactile quality of the surface is very important. To make a texture believable, you have to able to convey to the viewer exactly what the surface would feel like if they were to reach out and touch it. The art of creating textures is so much more than just defining the colours; it is about creating the quality and tangibility of them too.
The human touch
We humans have a remarkable effect on our surroundings. Every single day of our lives, we go from place to place, leaving our mark on everything that we touch. And this goes beyond just mere fingerprints and footprints. The way in whichc we handle items that we use determines, to a large degree, the manner in which they gather dust and grime, as well as develop telltale signs of wear and tear.
Consider this everyday example: your computer keyboard. No matter how frequently you clean it, you will never completely remove the marks that you leave on the keys. These marks may not necessarily be streaks of dirt, but a keyboard’s keys do become noticeably worn in a specific way over time. Eventually, the keys are going to develop a slightly different quality on the very spot, on each key, that your fingers generally touch. When texturing anything, you should consider what manner of human interaction, if any, affects the object on a regular basis. Consider not only the actual manner of interaction, but the frequency and purpose of such use.
My trusty old white Macbook’s keyboard has accumulated a lot of wear and tear over the years that I’ve owned it, as you can clearly see. Notice, in particular, how there’s a big clean area on the Enter key, where constant use has made it shinier and cleaner than the surrounding area.
Details like these help to not only make your textures more interesting to look at, but also makes them more believable. The key to believability lies in convincing the viewer that the object has some sort of purpose, and conveying the manner of that purpose by creating subtle details on its surface that give an indication as to what that function may be. Creating a sense of identity through idiosyncratic details in the textures you make for for your 3D models gives viewers an idea of where the item or character has been, and what it has been doing.
An absolutely essential tool for any texture painter is an excellent library of references. Whenever you come across a great picture of any kind of interesting surface, save it and stash it away for future reference. If you own a decent camera, take photos of detailed surfaces in your environment. You never know when these may come in useful. A texture painter should always work with references on hand – even highly experienced painters use reference. And they’re useful not only to you but also to your clients or supervisors, as you can look through your library when trying to decide what type of look to create for a model – choosing some ideas from a reference library is much quicker than spending a few days experimenting with ideas when nobody has quite nailed down what it is that they’re looking for.