How to achieve a polished steel look with spec/diffuse only?

[ablaine]

Hey guys, I'm wondering how one would go about achieving a polished steel look for armor and such in an engine like UDK, without using a shader/cubemap for reflections/fresnel. For example:


How do I achieve an effect like this using just diffuse, spec, glossiness/spec power, and such? It's probably just my limited knowledge of unreal and texturing in general, but I can't seem to get anything but a plastic look.

Thanks!

[StuBurrito]

Here are some nice tutorials, one is dedicated to making metal. May not be what you are looking for exactly but definetly worth watching. http://racer445.com/

[Beartastic]

Why? As a technical challenge, this is pretty strange. Reflective surfaces are best done using reflections. Blinn/phong shading is good for plastic and ceramics but doesn't work really well for metal.

You can hack it in if you want by painting the diffuse texture to look like it's metal reflecting from one angle and then sort of invert the reflected bits for the spec. It wouldn't look like a real reflection but it'd be a start.

[RavenShade83]

I think the main reason the material looks the way it does is BECAUSE of the reflections. I guess I understand why you're attempting it, but you're taking away one of the key physical aspects that make that metal what it is.

[chai]

You're out of luck - if you could achieve reflection without reflection, people wouldn't use reflection in games :P

However, you can make specular look less like plastic - by add noise to the specular map.
For non polished surfaces, I usually use dodge/burn, a dark diffuse with the specular brighter and higher contrast to break up the highlights.

[Mrpearlzildjian]

You're out of luck - if you could achieve reflection without reflection, people wouldn't use reflection in games :P

There is truth to that. An active object can have the "appearance" of metal, but not the properties of it with what you are asking for.

The only way I can see you able to fake reflection, is if the object were static. Then you could do something somewhat believable.

[Buzzy]

I think its possible....but its going to require a decent amount of shader code that essentially simulates a simple environment map. Probably not worth it because specular is very expensive already, and adding extra math to it is just going to make it worse than just using a cubemap.

Why are you trying to avoid an environment map anyway? I can't think of a real good reason really. In fact, I've started going the opposite direction with my art....I try to avoid specular maps and use environment maps whenever possible.