Steel and Rusty steel is a very useful material to have available for your renders. For me as a fantasy fan, they are common, but also for industrial, urban, sci-fi..well it can come in handy ;)

Vue comes with a rusty steel, but frankly its not that good. Its too much like a chrome ball bearing with patched rust, or maybe a galvanized tincan. Usually when an object rusts, the amount of rust, and over all oxidation varies highly, they also are rarely very highly polished. Depending on how the object has been exposed to moisture or corrosion, you can also see rust amounts low down, in dips etc.

Real world iron and steel for centuries was NOT the smooth, highly polished stainless steel we so often see today. It was usually hand made resulting in hammer marks, large, very shallow indentations, dents from use etc, except on the most expensive, highly polished work (in which case they ground it down for many days).
I personally dont have enough info to work out how steel/iron should reflect light and this set colours and so on, but you can come up with some nice tweaks in Vue for a nice olde worlde steel or iron.

First, lets make an antique looking steel.
Load STAINED SILVER, good start point.
Change the COLOUR production function, from Basic Repeater, to Filtered Fractal, Cellular, Vornoi. Largest feature 10, smallest 0. Roughness 0.5.
Remove the link to Colour output. Add a Maths function: Multiply (by about 0.25 or so)
Link this to Colour.
Now for the BUMP, add a texture node, and look for a texture. You want something elongated, lined. Best one is actually some barks, or if not make one using thin lines mostly in one direction, add some small blotches, blur it all. Hand made iron/steel has patina and lines form work/grain and folding.

Then set the SCALE of colour and Bump to 0.1
This should give a nice non-regular, look to the metal.

Set the Depth of the bump to about 0.85. Save your metal material.

Now we want to make a good Rust material.
Load up the Rusting Steel Material. Problem with this is we only want the rust, and rust is a features that pushes OUT from the surface, not in.
Connect the BUMP to the COLOUR fractal function.
Remove the other functions (reflection and highlight).
Now Edit Reflection in the normal material editor, set it to 0.
Save your RUST material.
Note that altering the colour and highlight colour can lead to variations on this theme.

Next step: make a new material, start with Antique steel, make it a MIXED material, add the Rust material.
This is where it gets funky, adjusting the BLEND modes can have very varying effects. Cubic bump makes thick blotchy rust, but stick to normal, set blending to about 60% and you get a varied, weathered rusted steel.
Also, you can set environment influences, OR use a texture to drive Distribution function, that way you can get rust build up in only specific areas etc.

And there you have it! :)

Note this same method can be used to make interesting corroded bronze etc.

Message edited on: 06/19/2005 10:55

Very nice! Thanks much, silverblade33. I encourage anyone creating realistic textures to take some time to gather and observe keenly (or photograph) real specimens first. Also observe various lightings on the specimens. And the photos may make good textures too.

XLT work! Thank You :)

very usefull !! thx

Hoep it works ok for you all :)) need to work on a good texture or function for Damascus steel, hm

Nicely done and greatly appreciated. Lin

Thanks, this will come in handy :o)

The picture is the material I made by following the tutorial and then free-styling. I rendered it on user-settings with a rather low quality threshold of 70%.

that came out good :)