PWx material types question

I was trying to explain 'material types' (under the material illumination
tab) to a guy in my office who is new to SW. My experience with the
software has apparently given me some blind spots, because his questions
pointed out that I've overlook how overly complicated it all is.



In a nutshell, his legitmate question was why do we have to change material
type to add components like reflectivity? Why can't reflectivity always be
there, and you just turn it from zero to some non-zero value?



Before I push on, I must explain why it matters. Lets say you have a
plastic material that you have tweaked so it looks great, but then realize
you need it to have a slight mirror component toi get it to look liek true
polsihed plastic. You will have to switch 'material types', and lose all of
those perfected settings as PWx silly defaults overwrite your hard work. If
PWx remembered the settings, that would be a half solution - my point is,
why not have all the fields up at once?



Here's the break down of real differences:



1. Constant - OK, this is useful; and stands alone.



2. Plastic=Matte, except matte has the specularity dialed down all the way
to matte (duh). Why bother with two different items?

Mirror=Conductor, in every single way - no values change at all!!!! Again,
why bother with a distinction?



Here's the unpleasant part: conductor=mirror=plastic=matte. The only
difference between them all is some settings are turned to zero. I have
tested, and manual changes in values of one type to match another produce
identical renderings. Why not just have one material type to cover all of
these?



In all of my custom materials, I have been using conductor for years and
until today never put my finger on why.



The caveat: The 'Metal' maerial type, which has no diffuse component, oddly
enough does not fit into the same rendering family as the four types
mentioned above. The renderigns turn out differently when all the other
settigns are set alike. This does not bother me, because I've never found a
use for 'metal', and (ironically enough) it seems neither has PWx - none of
the metals I've looked at in the stock materials actually uses the metal
material type!!! Also, I can't think of any real metal that does not in
fact have a diffuse component to it. I invite suggestions for why this type
exists



3. Glass=dialectric. These differ from category two because of the
introduction of transmission and refraction.
When you look at 'dialectric', it hints that it will be different from
'glass' because there is a slider for ambient and diffuse, but PWx does not
actually use either when rendering a dielectric (I have tested, and there is
not a pixel of difference in my test renders between high and low values for
ambient and diffuse on a dielectric)
The only issue is that renderings between 'glass' and 'dielectric' are
different, even with the same settings. The glass renders dark, and is
generally inferior (imo).

BTW - There are a couple of other material types relating to paint and
anistropic, but that is outside of my basic discussion.

So does anyone have a case for there to be so many different material types?
With my tests, at least four (matte, plastic, conductor, mirror) can be
combined into a single material, and a 'dialectric' type material with
transmission could be folded in if it truly had the diffuse and ambient
settings that the dialog box leads us to believe it has.

Also, does anyone have a case for why metal renders differently from plastic
with the same settings? Why glass renders differently from dielectric?

Just curious if I'm missing something important-
Ed

 

I agree. I'm not sure what the reason is. I often have to change the type
and start all over.