[smeggy]

This is the best way to add transparent marks like fingerprints and smears on glass, Also works great for scuffed plastics as these things only show up a lot when the light catches them right.

[MetinSeven_com]

And also very important: it allows you to adjust the harshness of highlights on glass.

[tom]

sorry, i'm not sure if its needed

[smeggy]

Why not tom? I can't think of any other way Maxwell can do this with dielectrics.

[tom]

Why not tom? I can't think of any other way Maxwell can do this with dielectrics.

Because, Adam's following explanation sounds good to me...

"I'm confused about the specularity channel. In other engines specularity is used to fake reflections of light sources. This shouldn't be necessary in MWR, as you can *only* have physical light sources (AFAIK). So why the spec channel?

Seems to me you would alter the reflection characteristics in MRW with a combination of glossiness and reflection maps, e.g., for a fingerprint you'd use the fingerprint map in the reflection channel to reduce the strength, and in the glossiness channel to reduce the sharpness."

...also Neil Blevins' following approach to speculars is worth to check
http://www.neilblevins.com/cg_education ... d_refs.htm

[smeggy]

As I stated in the other thread, we don't have a glossiness channel in Dielectrics, we don't have anythig except reflection, bump and color. Al I'm asking for is either glossiness or specular to work with.

In Neil's piece, he's entirely correct that these surfaces are still reflective, however, I'mnot talking about the actual surface itself, but a layer of crap on top of the surface which diffuses and scatters the light and basically kills the reflection (fingerprints for example are generally non reflective but semi-transparent and scattering). The specular isn't there to fake a reflection, it's used to kill the reflection and introduce a scattering effect over the surface where the crap lies.

I know it's difficult to explain and we're probably tqalking at cross-purposes on this so I'll leave it at this and hope someone recognises it's value as a tool

[tom]

once we have i mean

[smeggy]

Yeah, I tend to use specular and glossy as interchangeable in this case as either would work. Glossiness would do fine. It's all the same to me

[tom]

Oops, sorry. I didn't realize there was no glossiness in the dielectric material. Still confused about specularity in the plastic channel though.

yeah, specularity in the plastic mat. is strange smeggy

[smeggy]

Don't look at me, I'm just a visitor