- [Instructor] Just as the 3D max photometric lights
are physical simulation
of how light works in the real world,
the physical material is a simulation
of the surface properties of objects.
It fits into a physically based rendering workflow
and it's renderer agnostic.
That means it will look almost exactly the same
in any physically based renderer.
Before we work on building materials,
I recommend that we hide these material samples
over here in the material map browser.
The rendering of these samples
can slow down our interactivity in the material literature.
For performance reasons, it's a good idea
to turn off the rendering of those samples.
And there are several ways to do this,
the most drastic is to disable the little teapot icon
in the extreme, lower left.
When that's off, then you will get no updates
to any samples anywhere in the material editor.
And that's really no good because we need to see samples
in the graph or the view here.
So we'll turn that back on.
Another way to speed things up is to hide these icons
in the material map browser.
And the way to do that is to right-click
on one of the major categories such as materials
and from the pop-up menu choose
display group and subgroups as text.
And now we don't get any icons there
and we can do that for the maps category as well,
right-click on that
and choose display group and subgroups as text
and the scene materials too, right-click there
and display group and subgroups as text.
Now, the only icons will see in the material map browser
will be those in the sample slots
and that'll really speed things up.
We can prevent all samples
from rendering in the material map browser
by simply hiding the material map browser.
And I actually do that a lot because
I can create materials and maps directly in the graph
using a right-click menu.
If I don't need access to the scene materials
or the sample slots
then I don't need the material map browser at all.
And I can actually close it by clicking on its little X
and that'll give me more space for my graph.
If I ever need the material map browser back
I can find it in the material editor's tools menu
and I can bring that back if I want.
Let's create a physical material
right-click anywhere in the view graph,
and from the pop-up menu, choose materials,
general, physical material.
It's selected and its parameters are loaded automatically.
Double-click on the preview in order to make it larger.
The first parameter we need to look at is the material mode.
And when we first create a physical material
the material mode is set to
Autodesk standard surface compliant
and that means it's fully compatible
with other Autodesk applications, such as Maya.
If we change this to classic simple mode
that's really not helpful at all
because it hides many of the parameters.
The classic advanced mode has a couple parameters
that are not compatible with the standard surface.
And it is also missing some parameters
that are present in the standard surface.
So I don't recommend using that either.
I always have this set to standard surface compliant.
The physical material has some handy presets built into it,
and these can be helpful,
especially when you're learning how the material works.
At the top here we have some presets,
we can click on that pull down list
and let's choose glossy paint.
Once we have the glossy paint preset loaded
we see that our sample updates
and some of these parameters have changed.
We're dropped into classic simple mode.
We'll want to switch that over
to auto decks standard surface compliant.
This material's got a blue color
and it's got to roughness over here of 0.28.
Reflection roughness is probably the most important
of all the physical parameters.
Don't confuse it with the base color roughness up here,
just above it.
The base color roughness adds a layer
of micro fine diffuse scattering.
And that only applies you a few materials
such as unfinished ceramic,
but the reflection roughness
applies to all materials and it's super important.
A low reflection roughness
corresponds to a highly polished smooth surface
that will produce sharp, shiny reflections.
A high reflection roughness
corresponds to a dull or a matte finish.
The difference in reflection roughness
can be illustrated by selecting another preset.
Let's make a duplicate of this material.
Hold down Shift and drag to create a copy.
With that copy selected, go to the presets
and choose matte paint.
And again, change the material mode over
to Autodesk standard surface compliant.
These two materials are exactly identical
except for their reflection roughness.
This one here, the glossy paint
has a reflection roughness of 0.28.
The matte paint has a reflection roughness of 0.6.
We can see the difference here,
the glossy paint has a shiny highlight
and the matte paint has almost no highlight.
It's really spread out and quite dim.
Now, if the reflection roughness was at its maximum of one
then we would see no highlight at all.
I'll make another duplicate.
Hold down Shift and drag.
And in this third material
I'll increase the reflection roughness up to a value of one,
and now we have a completely matte finish
with no specular highlights.
Now, there's a gotcha
that you may run into with these presets.
Each one of these shading components
such as the base color reflections and transparency
has a weight factor.
That's a single number in a spinner
in the upper left of each one of these component sections.
That weighting factor
controls the contribution of that shading component
to the final result of the material.
We can, for example, dim down the highlights
by reducing the reflection weight.
The issue with many of these presets
is that the base color weight up here
is set to some value less than its maximum which is one.
We've got the base color or the Albedo here.
And that's the color of scattered light
it's reflected off of the surface.
We've also got the intensity of that color
the base color weight.
And in this, the base color is being dimed down.
It's being multiplied by a factor of 0.7.
And therefore the color that we choose here
in our base color itself is not going to match
the end result that we see in our rendering
even if the lighting is perfectly exposed.
So this doesn't make a lot of sense.
It's really a better idea to set the base color weight
to value of one,
and that way we see this is now brighter
and it actually matches this color swatch,
and we would get much more predictable results
in our rendering.
So I'll set all of these base color weights
to their maximum of one.
So we're not diming down the Albedo.
All right, so those are a few of the most basic parameters
for a physical material, the reflection roughness,
base color and base color weight.