Texturing of inorganic objects

In this tutorial I will show how to texture inanimate objects. Will try to describe the course of my thoughts. The lesson is written in the of makingof style and targeted at advanced 3d users. I will describe and explain my actions, but don't tell which buttons to press.



I have picked the door lock for the lesson


The first stage is analysis. It can be done both on paper and in the head. In order that would create a complex material it needs to be broken into components, and then in reverse order to collect on a three-dimensional model, step by step. In other words to describe the simplest characteristics of the material for easier comprehension. From the observations: for the good material is enough to realize 5 characteristics. More - better, but there is always a limit of time and effort.

So analysis:
Door lock is made of metal and covered with a layer of paint. Because it is not new, the paint peels off in some places and metal appears. Characteristics of the metal:
1. Grey color
2. Strong reflections
3. Scratches


Paint:
1. Blue-green color
2. Glossy reflections, weaker compared with the metal.
3. Dirt


Now about the relief:
1. The paint has a thickness and protrudes from the metal layer.
2. There are small bulges in some places on paint. This must be the air got under the paint during the painting.

What are we going to work:
Model of the lock (or part thereof):


Unwrap:


Light sources placement:


Lets make metal material:
Add reflections. Grey color is shifted slightly to darker. Few test renders and:




Now remains to add scratches. I took this texture:


In Photoshop I align and scale it according to unwrap. Scratches usually have a strong reflection. Glossiness in the settings of the material in the numerical representation, and therefore to choose right color you need to multiply this number by 255. In my case 0.73 * 255 ≈ 186.


Render:



Turning to the configuration of the material of paint. I am taking into account characteristics described above.




Seeking a texture suitable for my needs


Tiled more neutral upper part. Dirt added in Photoshop. In order to make a better understanding where to place dirt i made "dirtmap".


Different ways to create dirtmap i will describe in separate tutorial.

Dirt has dark gray color and less glossiness. Located predominantly in the center of pits.


Render:



Now, in order that would combine both the material needs a mask. White areas - one material, black - the second. Nothing complicated, just painted white with a brush in Photoshop where paint is peels off.


How it looks in material editor:


Render:


Now turn to the final stage - relief.
As a basis for the displacement map i used a previously created mask. I added a bit of white spots, indicating the place where the paint is swollen.


Final render:


That's all. Feel free to ask any questions. They can inspire me to write new tutorials.