Help with Black painted metal

[Torsten]

Hi Rimas,

The material keeps getting better, i like the way you use a fallof to provide somewhat of a gloss to the materials, resulting in nice hightlights. I attached the material put on the objects in my scene. This is without the surrounding building geometry. It works great. Putting the stuff inside of the house, it becomes dull without the nice hightlights. So indeed the lighting, as you already have mentioned, needs to be better (not just HDRI).

Can you explain to me why you use the 'Towards-Away' fallofin the reflection glossiness of the base black? I am always used to put perpendicular-parrallell into it. But changing the fallof type to the latter, it becomes way more reflective.

Thanks!

[Juraj]

I will give advice that was also echoed by Bertrand Benoit in his Speech two years ago (but I did it forever and shown similar approach in my speech year ago :- D .. )

Don't test materials in abstract space of some arbitrary HDR. Esp, when that is not what is happening in your reference.

Test them in space you will be rendering them in. The light direction, overall lighting levels,environment,  etc.. dictate the look.

Few notes: Always make sure if your object is actual metallic surface, or painted surface. If paint, then if it's metallic paint or not. This largely dictates the reflective curve but also if you have diffuse albedo at all (metal don't)
High frequency vs low frequency detail : Metallic thin surfaces (like plates) are always crooked. It's hard to simulate with bump, subdivide your object and put noise modifier or paint over vertexes manually in edit poly mode.
Layering: Surface can often have multiple coatings. Thin glossy overlay + super thin 'thin film' layer is the ultimate overkill, but may give the best look if that's how your reference works.

But if you disable fresnel and just use the custom fall-off you'll just end up with a very reflective material

No you don't. If you use Fall-off, always disable fresnel. Otherwise you double the effect, which is just wrong. If it's too reflective, then your fallof is wrong. You can use fallof to simulate any kind of reflection, even super dim.
Has nothing to do with fresnel.

[Rimas]

But if you disable fresnel and just use the custom fall-off you'll just end up with a very reflective material

No you don't. If you use Fall-off, always disable fresnel. Otherwise you double the effect, which is just wrong. If it's too reflective, then your fallof is wrong. You can use fallof to simulate any kind of reflection, even super dim.
Has nothing to do with fresnel.

Hah, I kind of mumbled there and realized it, hence it was fixed in the later addition after my comment (the second scene no longer contained doubled-up fresnel) :D
Thanks for the insights tho!

It is indeed true that testing a material and trying to have it look the same as reference in a totally different scene is impossible, hence why I also built a quick boxmodel with some lights somewhat similar to the reference (I didn't pay attention about the scale and stuff tho' due to time constraints, so it's arguable :D).

[Rimas]

Can you explain to me why you use the 'Towards-Away' fallofin the reflection glossiness of the base black? I am always used to put perpendicular-parrallell into it. But changing the fallof type to the latter, it becomes way more reflective.

Thanks!

In a totally non-scientific way of explaining things - the fallof map now represents the response curve, similar to what you have with refrection BDRF. I was just eyeballing the look of the material within my scene if I'm honest. Usually it's best to have a piece of actual physical reference or to go to a showroom and have a look at the material from different angles and take pictures, but in this case it's not possible and there is no description or swatches, so the best thing anyone can do is eyeball it, especially if it's a material that you have no experience with.