This single physically-based shader

can be used to make such a wide variety

of materials it's easily

possible that this one shader can make

every material in a given project.

The standard is used to create Unity's default material.

So all mesh rendered using

the default material will be using the standard shader.

All new materials that are created

will use the standard shader as well.

To change the shader used by a material

select the Shader menu on the material.

Select Standard to use the standard shader.

It is worth noting the Unity

has shaders available for both

popular approaches to physically-based rendering.

Metallic, as default,

and specular.

To choose the standard shader

using the specular approach

select Standard (Specular Setup).

Otherwise use Standard

for the metallic approach.

It is important to understand that the

metallic approach to physically-based shading

is not only for materials which are

supposed to look metallic.

This mode is known as metallic

because this approach is based on

defining how metallic or non-metallic

that material's surface is.

This is opposed to the specular approach

which defines how specular,

or non-specular that surface is.

Both approaches are valid ways to

describe a physically-based material.

This physically-based material is

still a standard Unity material

and this material is associated

with a renderer in the same way as usual.

There are three sections to the standard shader.

Rendering Mode.

Main Maps

and Secondary Maps.

The standard shader has four rendering modes.

Opaque, Cutout, Fade and Transparent.

Most materials are opaque, or solid materials.

Opaque is the default render mode.

For transparent materials, such as glass,

choose Transparent.

In transparent rendering mode

the alpha channel on the diffuse colour property

is used to control the level of transparency.

With rendering mode cutout

the alpha channel of the diffuse image

is used to mask out parts of the texture.

If the alpha channel has a gradient value to the mask

the alpha cutoff slider can be used

to adjust the shape of the cutout.

based on the strength of the mask in the alpha channel.

Rendering mode fade is similar

to rendering mode transparent.

Fade is intended for fading out

game objects on screen.

With rendering mode transparent

a transparent material will preserve it's

reflectivity regardless of it's alpha value.

Fade however will fade all

relevant aspects of the material

so the faded material is completely invisible.

The main map section defines the look of the material.

Before going in to the details of each property

there are a few subjects that are worth covering first.

Optimisation.

The standard shader is highly optimised.

When the standard shader is built

two important things happen.

All properties that are not being used are discarded.

The build target is checked

and the shader is optimised for that device.

Because of this there is no need to populate every

property with a map or values.

And there is no need to worry about wasted

resources due to unused properties.

Physically-based shading.

Physically-based shading tries to define

certain physical aspects of a material's surface.

Including it's diffuse colour,

specular refection and other properties

so the material behaves correctly

and believably in all lighting environments.

The response of the scene lighting to the material

created with a physically based shader

mimics light in the real physical world.

This means that even though there is

full control over the values on

all of the properties in the standard shader

there are certain ranges of values that

work best for certain types of materials.

This is particularly true of the metallic and specular values

depending up which approach is being used

Taking specular colour for example,

when analysing real-world materials

most materials have a specular range

that is a very dark grey.

Metals created with a specular workflow are one of the few exceptions,

they have very bright specular values.

As well, no material, even the most dull,

has no specularity at all.

This means to have a physically based

material behave correctly

some attention needs to be paid in using

the correct physical values for some key properties,

especially the specular or metallic properties

depending upon the approach being used.

For more information on physical-based shading,

material charts and sample materials

please see the information linked below.

There is no need to panic however.

Items with materials from previous versions of Unity

will work well out of the box.

Upgrading from a legacy diffuse shader

to the standard shader should display little or no difference.

In the main map section each of these properties

control one aspect of the final material.

Each property can be defined by a texture map.

With the metallic approach,

for the albido, metallic and emission properties

the texture is optional.

The albido and emission properties

can simply use a colour value instead of a texture.

The colour value is not available on

the emission property until the emissive

scale is larger than 0.

The metallic property can use a slider

instead of a texture.

The albido property uses a

combination of an optional texture.

And a colour value to define the base look of the material.

The colour value will tint the texture.

Where pure white leaves the main texture unaffected,

if there is no texture being used

the tint colour will be the base colour for the material

The metallic property can be defined

by either a texture

or a value from 0 to 1

set by the slider.

This defines the metalness of the material surface.

Metalness works very closely with smoothness.

The smoothness property is used to

control the smoothness,

or micro-surface detail, of the material.

It is also a value between 0 and 1.

The less smooth the surface is,

the more diffuse the reflections will be.

The more smooth, the sharper the reflections.

The metallic property can use a texture

to define the material's metalness.

This texture can be a simple shade of grey

used to define the metalness from black,

or non-metallic,

to white, completely metallic.

However, the advantage of using a texture

to define the metalness of a material

is to vary the metalness value

across the surface of the material.

An additional advantage is this texture's alpha channel.

This alpha channel can be used to define

a smoothness map.

Many materials are far more complex

than a single uniform surface.

Take this leather case for example.

With a single value for metalness and a

single value for smoothness

the case looks good.

But it could look better.

Use a metalness and smoothness map

to describe the properties.

And it looks much better.

Note how the straps are far more glossy

than the main body of the case.

Giving them a feel of polished leather.

It is worth noting that when using a texture

to define the metalness

the smoothness value must also be

defined by that texture's alpha channel.

It is also worth noting that the metalness

value is stored only in the red

channel of the metalness map's RGB values.

The green and blue channels are ignored.

It is often easier however to visualise

the metalness values of a texture

if all three colour channels share the same map,

so the texture appears as a greyscale image.

When using the standard shader with the specular setup

the metallic property is replaced with

the specular property.

The specular approach also uses

a smoothness property, which behaves essentially

in the same way as with the metalness approach.

The specualar property can either be a texture

or a colour value

and defines the specular reflectivity

of the material's surface.

The specular value can have some colour in it

but looking at real world values

with the exception of some metals

this is usually a grey and often very dark.

Specular maps are usually a dark grey as well.

When a specular texture map is not being used

the overall surface smoothness can be

set with the slider.

This is easier to see when the albido

texture is removed.

The ball looks like polished porcelain.

For a more true mirror, the specular from dark grey,

which makes the ball look like porcelain

in to the range of metals and it will now

reflect the sky and surroundings.

The smoother the surface, the more it is mirror-like.

The rougher the surface the more diffuse,

or scattered the reflections are.

The normal map property is an optional property

used to define the apparent bumpiness of the surface.

When a normal map is applied

the strength of the normal map can be controlled

by adjusting the normal map value.

As well as positive numbers, this value

can be a negative number

or 0.

The height map property is an optional

property used to define the apparent

height of the surface.

When a height map is applied

the strength of the height map can be controlled

by adjusting the height map value.

The occlusion property uses a

texture map to define the amount of

ambient occlusion that is applied to the material.

This is used to help darken

hidden or recessed areas on the texture.

The ambient occlusion map also

prevents specular and reflections in

these occluded areas, given the material

a more realistic look.

The emission property controls whether or not

the material's surface will emit light.

The material's emission value can contribute

to the scene's global illumination.

The strength of the emission can be controlled

by the emission value.

The shape of the emission can be controlled with an emission map.

The map can be a simple black and white map.

bBut this texture can also be a colour map.

When there is a value for emission

the contribution of the emissive light

can be assigned to either the baked light maps

or to the real time light maps.

The detail mask property is an optional mask element

to control the secondary maps.

Tiling and offset control the position of the map.

The secondary maps are used to define

additional surface detail.

This additional detail, sometimes referred to as micro detail,

is added on top of the surface defined