Brushed Metal Material
By Neil Blevins
Created On: Aug 21st 2005
Updated On: Dec 9th 2013

Brushed Metal is a metallic surface that's covered in small scratches that causes the metal's reflection to be blurred.

Before following this tutorial, please read my tutorials on Reflections And Highlights, Anisotropic Reflections In The Real World, Anisotropic Reflections In CG Software and Chrome Material.

Polished Reflection vs Blurry Reflection vs Glossy Reflection

So you may hear a lot of definitions being thrown around like a polished reflection, a blurry reflection, or a glossy reflection. Defining these is actually a little bit difficult since these words can mean different things to different people and in different renderers. But here's the general gist of things.

Glossy reflections also come in two flavors, Isotropic and Anisotropic.
Isotropic Brushed Metal

Lets start with Isotropic brushed metal.

Blurry Raytraced Chrome

The basic ingredients are as follows:

Now that we have the theory, lets show how to create the effect in 3d using a number of different 3d apps and renderers.
Blurry Raytraced Chrome

3dsmax's Brazil Advanced Material in Brazil Rio Renderer

Here's an example file to make a scene like the image above using 3dsmax's Brazil Renderer: blurred_raytraced_chrome_brazil.zip (Requires 3dsmax 5 or later, Brazil Rio)

This is identical to the chrome in the Chrome Material tutorial, except I turned on Brazil's Glossy Reflection Control, and set the Glossiness to 60. Now the reflections will be blurred. Play with the Max Error value to find the perfect balance between speed and image quality.

3dsmax's Arch & Design Material in mentalray Renderer

Here's an example file to make a scene like the image above using 3dsmax's mentalray Renderer: blurred_raytraced_chrome_mr.zip (Requires 3dsmax 2009 or later, mentalray)

Again, identical to the polished chrome, except I changed the Glossiness from a value of 1.0 to a value of 0.23. I also increased the Glossy Samples to 32, so that the blur is nice and smooth, without tons of noise.

3dsmax's VrayMtl Material in Vray Renderer

Here's an example file to make a scene like the image above using 3dsmax's Vray Renderer: blurred_raytraced_chrome_vray.zip (Requires 3dsmax 2014 or later, Vray 2.4, ColorCorrect)

Again, identical to the polished chrome, except I changed the Refl. glossiness from a value of 1.0 to a value of 0.8. (note, the env is wrapped in a ColorCorrect map to set the gamma correctly, since this scene uses Linear Workflow). I also increased the Subdivs to 32, so that the blur is nice and smooth, without tons of noise.

Blurry Environment Mapped / Polished Environment Mapped and Raytraced Chrome

Again, in the Chrome Material lesson I also mention these two other types of Chrome. To make the same materials, just follow the Chrome instructions, and then turn on the Glossy controls mentionned in the examples above.

Anisotropic Brushed Metal

Now lets move onto Anisotropic Brushed Metal.

Anisotropic Brushed Metal Using Small Bumps

Since anisotropic reflections are really just reflections distorted by tiny bumps on a surface, why not just make those fine bumps on our cg surfaces? Well, you can, for example, take a look at the tea kettle that I rendered in Ghost (the predecessor to Brazil)...

Tea Kettle

So the basic ingredients are as follows:

Now that we have the theory, lets show how to create the effect in 3d using a number of different 3d apps and renderers.


3dsmax's Brazil Advanced Material in Brazil Rio Renderer

Here's an example file to make a scene like the image above using 3dsmax's Brazil Renderer: aniso_with_bumps_brazil.zip (Requires 3dsmax 5 or later, Brazil Rio)

First, make a polished raytrace chrome surface. Then add a very soft, small but elongated bump map, which distorts the reflection primarily along one axis.


Remember, you don't have to use a noise procedural map like I have in this file, you can also use painted maps for your bump, as long as the bumps are fine enough. So, for example, if you have the top of a cylinder, you could paint a map that has scratches going in a circular direction, and then map it to the top of the cylinder. It'll look like the top of a CD, or the bottom of a pot.

While this technique works, it takes a lot of fine tuning to get just the right size and frequency of bumps to produce the type of distortion you want.

3dsmax's Arch & Design Material in mentalray Renderer

This is identical to the chrome in the Chrome Material tutorial, but then I add the bump map shown above.

3dsmax's VrayMtl Material in Vray Renderer

This is identical to the chrome in the Chrome Material tutorial, but then I add the bump map shown above.

Anisotropic Brushed Metal Using Anisotropic Reflection Shader

With an Anisotropic Reflection shader, you can stretch the reflection without the need for a fine bump map (although adding bumps does make the effect look more realistic). Much like an anisotropic highlight, you have control over the amount of anisotropy, and the reflection gets stretched in the direction and by the amount you choose.

So the basic ingredients are as follows:

Now that we have the theory, lets show how to create the effect in 3d using a number of different 3d apps and renderers.


3dsmax's Arch & Design Material in mentalray Renderer

Here's an example file to make a scene like the image above using 3dsmax's mentalray Renderer: aniso_shader_mr.zip (Requires 3dsmax 2008 or later, mentalray)

Create an Arch & Design material, set it up as blurred raytraced chrome, and now set Anisotropy to a number lower than 1, the lower the number the more stretched the reflection. Also note, I placed a stretched noise in the reflection amount just to get something that looks a little bit like scratches. But note, these scratches aren't distorting the reflection, the anisotropic controls are.

3dsmax's VrayMtl Material in Vray Renderer

Here's an example file to make a scene like the image above using 3dsmax's Vray Renderer: aniso_shader_vray.zip (Requires 3dsmax 2014 or later, Vray)

Create an VrayMtl material, set it up as blurred raytraced chrome, and now set Anisotropy to a number above 0 (but not 1). Also note, I placed a stretched noise in the reflection amount just to get something that looks a little bit like scratches. But note, these scratches aren't distorting the reflection, the anisotropic controls are.

Anisotropic Brushed Metal Using A Reflection Map

Similar to the first example, but you use a pre-distorted reflection to make it appear as though it's anisotropic. So say we have the following reflection map...


That produces the following reflection on our cylinder...


Now take this reflection map and use the motionblur filter inside photoshop on it going vertically, amount depends on how much of the effect you're after. You get something like this...


Now the reflection looks anisotropic, although it's not the surface causing the anisotropy (like in real life), but the reflection itself that's been pre-blurred to appear anisotropic...


And now add a little noise in the bump slot (or even the diffuse slot if you'd like) to simulate the grain you see in anisotropic metal.

Note, the noise doesn't have to be as small as the noise I used in the "Brushed Metal Using Small Bumps" above, because we're not using the bumps to distort the reflection, we're just using the bumps to look bumpy.

Also note, the direction of the grain should always go in the opposite direction that the reflections are stretched. This happens automatically when you're actually using the grain to distort the reflections, but you need to keep this in mind when doing this sort of cheat.


Of course, this trick only works with a reflection map, you can't use it to distort real raytraced reflections. But you can mix and match, do a pre-distorted environment map and then mix it with real blurred raytraced reflections.


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