When you’re making metal in 3D, one thing that adds a bit of depth and detail to your object is a brushed look. As most people know, brushed metal is used for a lot of things; name plates, plaques, gun barrels, aluminum tubing, plumbing, movie props, etc. Getting a nice brushed look is actually easier than some people might think. A few years ago, I was looking for a brushed metal texture after a friend suggested it and I stumbled across a tutorial to make your own. I don’t remember where I found the tutorial or who published it or I’d give them credit. I think it was a Photoshop tutorial but, like most “Photoshop” tutorials, it can easily be done in other software. In this instance, I’m using GIMP 2.8.
For starters, decide what you’re texturing and then make the texure the correct size. If you’re wrapping a cylinder/tube, which is a common use of brushed metal, you’ll want a texture that’s taller than it is wide. For flat brushed metal, simply use the object you’ll be texturing as a guide to determine the image dimensions. For the purposes of this tutorial, so that the image will fit in the space so that all of it can be seen, I went with 400X600, but you’ll likely want to make a higher resolution image than that.
Tip: Standard UV mapping coordinates are: X= vertical Y=horizontal. (Z doesn’t apply)
So, you have a blank image:
Next, you’re going to want an RGB Noise filter. In GIMP, that’s under Filters>Noise. Go with pretty high settings on the noise so that it shows up darker and make sure it’s in grayscale (though, that last step can technically be done later.):
Those are example settings, you can do what you want. However, it will get lighter in the next step. Once you have it set where you want it, hit OK:
Once you’ve done that, find the Tileable Blur tool. In GIMP, that’s under Filters>Blur. You want to blur horizontally only. Again, these are example settings:
Once you’re done with the settings, hit OK and you’ll get the following:
Technically, you’re done now. You can apply this as a bump map to an object with a gray color and some reflection and call it brushed metal. However, if you want a bit more depth, you can also use this as a color map. You probably don’t want it to be black and white, so you can make it more gray by fiddling with the Brightness-Contrast. In GIMP, that’s under the Colors menu. (Though, I’d advise saving the B&W one as a bump map) Here are some example settings:
Also, you can do color brushed metal maps by simply playing with the Colorize tool, also in the Colors menu in GIMP. Note: do this after you change the Brightness-Contrast setting because it won’t colorize white or black:
Lastly, just to show you how well this works, I used that method to texture the brushed metal parts in this lightsaber hilt that I made a couple years ago in Blender: