Some help with lighting black gun metal material

# 1 25-04-2008 , 03:02 AM

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Some help with lighting black gun metal material

Hi,

I'm modeling a gun and having a little trouble getting the material correct. I've made some ok metal materials previously by creating very dark, low diffuse materials with a fairly high, blurred material. This is black gun metal though.

In the first image, it is lit with an hdri globe. In the second, just a directional light and a light background. Both use FG.

I've tweaked the spec levels, and added varying degrees of reflectivity (blurred in the MR settings) but can't really get something nice.

Does anyone have any experience/advice of creating a nice, black metal material? Is so then please share.

thanks

gubar

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# 2 25-04-2008 , 03:03 AM

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Here's the second image. The problem I have is that no detail is really visible on the gun resulting in a dull render. Increasing the specularity does help but doesn't really represent the gun as it appears in life.

cheers

gubar

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# 3 25-04-2008 , 03:53 AM

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Do you have anything for it to reflect?

"No pressure, no diamonds" Thomas Carlyle

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# 4 25-04-2008 , 03:57 AM

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In the top image, there is a ground plane an environment sphere.

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# 5 25-04-2008 , 04:03 AM

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The top image dosent look too bad.

Have a play with the spec colour overcranking above 1

Did you use a fresnell of the reflectivity at all?

"No pressure, no diamonds" Thomas Carlyle

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# 6 25-04-2008 , 04:13 AM

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Cheers gster I'll try that spec advice and post back later.

You've pre-empted my next question... if I'm correct I connect the facing ratio of a sampler info node into the reflect and spec channels right? I've read in one place connect it to the y, in others, the z. What would you advise and is there any difference? Is there a way to get a scientifically correct ratio using the ramp values or do you just tweak? Black at the top of the ramp or the bottom? etc

You're probably wishing you hadn't bothered replying now, just looking for a quick guide to applying these. I tried before and wasn't convinced by my result.

thanks

gubar

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# 7 25-04-2008 , 08:32 AM

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Spec is actually a way of faking reflection highlights, be aware of that, but yeah in both.

Theres no difference as long as you use the right type of ramo for the input, a U ramp for the U input and a V ramp for the V input, otherwise you get it the worng way round and it wont do what you want it to no matter what the values.

yeah just tweek it till you get it right, making sure that you values are correct to start off with, if its on the spec you can have a preview in hte material node and then renderto tweek it to how you want it.

"No pressure, no diamonds" Thomas Carlyle

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# 8 26-04-2008 , 04:59 AM

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Thought I'd post a bit of an update. I should also mention that this is based on a 3dbuzz tutorial, credit where it's due, though I've changed the mesh significantly and added some detail and the materials.

Got some better success by altering the spec, and increasing the reflectivity and adding heavy blur to it. Still to add the fresnel. Cheers for the input gster.

gubar

edit: I forgot to ask gster or anyone else checking the thread... on which channel of specularity is the fresnel best applied, eccentricity, roll of or colour?

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Last edited by gubar; 26-04-2008 at 05:02 AM.

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Some help with lighting black gun metal material

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