Over the years I've learned and developed my own solutions and methods for complex texturing. The blood knight is the second of several characters I'm making and since he's the one who experiences the battle up close and personal, I've decided that with him I will try to push my methods and add lots of details such as dirt, scratches, stains, blood, decorations etc using a method I like to call "multi-channel texturing". My main focus on this character was the texturing / shading and in this tutorial I will share the process, considerations and a few other tips (Fig.01).
Multi-channel texturing - general idea, pros and cons
The method I refer to as multi-channel texturing takes advantage of the ability to have many different map channels (in other software, like Maya, these are referred to as UV-sets) for the same object, while it's material is made out of many maps mixed together using masks with these map channels.
In other words - almost the entire texturing process of the character's armour parts is done within Max, through the UV's and using only one material and a few textures.
The end result of this is that all of the armour's parts (over 40 different objects in the blood knight's case) use the same material, with just a few textures. This is opposed to the "classic" texturing method in which you end up with many materials and hundreds of different texture files (assuming each material will have several textures for colour / bump / specular etc') (Fig.02).
- Major resource saver - all of the armour parts use only one material and a few textures for everything.
- Since many of the textures are applied in tiling, it allows for very high res details at a relatively low resources cost.
- Immediate feedback from within the viewport as to where details fall. This is especially helpful when working on things such as the side decorations, which can be deformed specifically to the shape of the mesh (which is rather hard to do with UV's / Photoshop using "standard" methods).
- Ability to quickly clone your models and create many variations in the textures by simply altering the UVs (if I wanted to make many clones of this character with variations in the details such as scratches, blood stains, dirt, I wouldn't need to create new textures, just play around with each clone's UV'S)
- Somewhat limited control for specific details (making "global" textures that will be used for all the model's parts kind of limits you if you want some parts to have unique details without making new textures specifically for them).
- The material tends to be heavy and give slow feedback in the material editor when "show end result" is on, due to its complexity. The more details you add, the heavier the material becomes and it does get harder to keep track of everything.
Fig.03 shows a few close-up examples of the multi-channel texturing technique.