The cooper turret created in the previous recipes may be accurate in terms of color, and aging of real copper, but sometimes it's useful to go beyond reality and add other textures to dirty a material simulation just because it looks better. We can do this with our simulation by adding two further textures.
This recipe uses the blendfile saved at the end of the last recipe. If you have not completed that recipe, you can download the following file from the Packtpub website:
We will begin by adding a repeated texture to mix a lighter green color to the areas of the turret not masked by the blend but controlled by the specularity image map. ...