Quote - BB, two questions

Q1 why did you pick Blinn in your proposed shader?

As I would be inclined to use Blinn for specular effects on porous, soft materials and Glossy (or KS_microfacet) on hard, smooth, nonporous stuff like glass.

1. Because I don't need the automation offered by KS_Microfacet - I know how to configure Blinn to produce numerous different roughness values and match it to the correct brightness.

2. I have carefully matched Blinn to reflect softness over thousands of experiments. I would have to start over with KS_Microfacet since I don't know its parameterization.

3. I have demonstrated that KS_Microfacet is flawed in certain rim-lighting situations, and Blinn is not.

4. I have demonstrated that KS_Microfacet is flawed with high blur - it does not pick up what might be called secondary facet-to-facet reflections in areas away from the hot spot.

5. Blinn is available in all versions of Poser.

(Before you point out that I used Fresnel_Blend which is also not available in all versions of Poser, I have a 5-node substitute for those that need it. I was trying to keep things simple so 1-node trumped backwards compatibility in this demonstration.)

Note: Glossy is not about gloss - it's about pretending the point light sources actually have dimension. The correct setting for Glossy would depend on many factors, but would basically be applicable when pretending that a point light is actually a circle - you would then be configuring it to produce a specific circular diameter for your pretend light source. No real life material actually behaves as Glossy does when exposed to a point source. Blinn does behave as real life when exposed to point sources.

I include the infinite light as a point source in my explanation. Since I was doing sunlight, Glossy would not be applicable.

There is also a flare or halo around the Blinn specular that is correct and is missing in Glossy when you need Glossy to produce a small dot of light. Most people don't know this because they operate Blinn with too low a reflectivity value. Note that I combine the super high Blinn reflectivity with the reflectivity reduction found in a Fresnel shader (whether by Fresnel_Blend or more nodes - if it obeys Fresnel's law, it's a Fresnel shader.). If you just do one without the other, you're going to get confused.

Quote - Q2 what about your remarks on the Reflection slots in PoserSurface, what's wrong with them? As I woud be inclined to use Value for reflectivity as long as Color has a 100% brightness and provides Hue/Saturation only (for metals, that is). And Value is just a multiplier to Color anyway (besides gamma which is affecting Color but not Value). No?

When you set a surface to 100% transparent, it still emits some of the data from Reflection_Color. At other percentages it emits more Reflection_Color than would be justified by the opacity. The amount is unclear to me, as it is undocumented and I have not done any experiments to extract that detail. Since I'm trying to produce exact amounts of reflection, under my control, that match reality based on the Fresnel effect, I prefer to have no hidden magical incantations in my shaders.

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Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)