Highlights
Lets start with the highlights. Brushed metal has anisotropic highlights. In short it means that the highlight isn't a round white spot, but instead lots of small parallel lines. I won't go into detail on how it works, Neil Blevins has an excellent explanation of that. Suffice to say that the anisotropic highlight option is the one we need for this job. Unfortunately, the raytrace mat doesn't support it which means we'll have to use the Shellac material. Click the Raytrace button and pick Shellac, Keep old material as sub-material. It should look like this
Click the Shellac material, name it "Anisotropic Highlight". Change the ambient and diffuse colours to black and tweak the specular and glossiness settings. You can use the image as a guide. Place an instance of the bigmix map in the bump slot and the specular slot.
The reason for this is to break up the highlight and add to the realism. It's important to remember that the shellac material isn't affected by the bump map in the underlying material, which means you have to instance the bump map if you want the highlight to react according to the underlying surface. In short, without a bump map, the highlight would just "glide" on top of the bump map in the Brushed material. Which would look bad. Another good thing is by using instances, you get fewer maps to edit which speeds up any changes you make. Lastly, turn on supersampling. Hammersley is a good choice for bumps which we have a lot of in this material.
Go back to Raytrace material (Brushed) and adjust the highlights. Since the shellac material (Anisotropic Highlights) creates the main highlight, we don't need a strong specular on the raytrace mat. I used very low values overall
The reflections
And now for the render intensive part: blurry reflections. The raytrace material supports blurry reflections, although they are evenly blurred and not anisotropic blurry reflections. But they are sufficient for this material. Open the Raytrace Controls rollout. Here you can add a neat effect: reflection falloff. It fades the reflection to a specified colour or the background after a set distance. This together with blurry reflections adds a lot to the scene. To get the blurry reflections, turn on Global Antialiasing Settings. Click the three dots to open the Global Raytracer settings. Select the Fast Adaptive Antialiaser, click the three dots in to open the F.A.A. settings dialog. Here you can specify the defocusing and blurring of the reflections. I really recommend that you sit down and render a few tests with it and read the documentation about these settings. You might need to adapt these settings to your scene in the future.
To give the reflections a final touch, put a Falloff material in the reflect slot, name it fresnel. Change the falloff type to fresnel and uncheck "Override Material IOR". Change the IOR in the Basic Parameters to something around 8,0. This makes the object more reflective on the sides and less reflective head on.
The last map is another Falloff map in the Ambient slot. This uses the default values and is just a nice touch to fake bounced light from the environemnt. You can leave it out if you feel like it or if you are using a true GI solution.
That's it. With some luck, your material should look like this when magnified in the Mat.ed.
Here's the mat.tree in all it's glory. If you look at the names, you'll see that it's all instances...
And as a bonus:
The Scene, Max 4 version.
This last paragraph is for professionals only, USE AT YOUR OWN RISK!
The short short short version
You can do it like I did with this tutorial, or as a friend of mine (named Iain) put it:
- Create sphere
- Apply grey material
- Periodically show it to people who are never satisfied and tweak it until it looks great.
I hope this tut has helped you in some way. If you have any questions, comments, praise and/or job offers, feel free to mail me or drop by #CgTalk @ Freenode.net. I usually go by the nick Urgaffel or Urg|(something).
Big thanks go to the people in #Maxforums!
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© Peter Åsberg 2001