Textures

A texture is an image file.

Unity uses textures in a number of different ways.

The most common use of a texture is when

applied to a material in the base

texture property to give a mesh a

textured surface.

For more information on materials

see the appropriate lesson.

Textures can also be used for

GUI elements applied to additional

material properties to act as normal

maps, specular maps or height maps.

Used as custom cursors, icons,

splash screens and more.

Textures can be any image file

supported by Unity.

These can be photos straight from a

digital source, but textures are usually

images created or manipulated in an image

editor, like Photoshop or Gimp.

It is important to note that the layered

files will be flattened on import

but the layers are maintained in

Unity in the original file.

This means we can turn layers on and off

without loss when we're setting up our game

but when we're running our game we will not

have access to these layers individually.

Most of the image file formats used by

Unity support transparency.

The notable exception is JPEG,

which does not.

For more information on transparency

and how to use it, see the documentation on

materials and shaders.

Texture files should be saved in the assets folder.

Unity searches the assets folder

in a specific order when seeking materials.

For more information on searching for textures

and seeking materials see the lesson

on mesh importing.

A texture file should be assigned import

settings in the texture importer.

Texture Type property contains a

list of presets.

These limit the number of editable properties

available in the texture importer

based on the intended use for the image.

The default is Texture.

Advanced will expose all of the available

properties in the texture importer.

The other presets, including advanced,

will be covered in another lesson.

If we need to set the transparency

or alpha channel for the texture automatically

based on the light and dark parts of the image

we can check the Alpha From Greyscale field.

Black will be completely transparent,

white will be completely opaque.

Wrap Mode controls how the texture is mapped

on to a renderer when tiled.

This setting works for both 2D elements

and 3D meshes.

Repeat will repeat the texture and

and Clamp will stretch the edges of the texture.

Filter Mode controls how the graphics

card renders the texture,

when it is stretched by 3D transformations.

These are effectively quality settings,

trilinear being the best and

point being the most basic.

Aniso level controls the quality of

textures when rendered at steep angles.

Anisotropic Filtering increases the

texture quality when viewed at

a grazing angle.

This has an increased rendering cost when applied.

In quality settings, Anisotropic filtering

can be forced on for all textures

or disabled completely.

For more information on quality settings

see the appropriate lesson.

Because Unity supports building to

multiple target platforms from one project

the texture importer allows for a default

setting for max texture size

and compression format that can be

overridden on a per platform basis.

Max Size will set the maximum size for

for the imported texture.

If max size is set to a value larger

than that of the original image the size

of the imported texture

will be that of the original.

This setting will not make the texture

larger than the original image.

If max size is set to a value less

than the original image the texture will

be resized to that value on import.

Like layers, however, the original

file is unchanged.

Only the imported asset will be adjusted.

Format sets the compression technique.

The default settings are relatively simple

when using the Texture preset.

These are effectively quality settings of

low, medium and high.

More control can be set on a per

platform basis, or when using the Advanced setting.

Each target platform can have it's own settings

that override the default values.

Max size and compression can be adjusted

for each target platform.

This means we can set the target sizes

and compression appropriate for the

bandwidth and processing power

of the target platform.

When the build target is changed these

assets will be reimported using the

overridden values.

This section works in conjunction with Build Settings.

For more information on Build Settings

please see the appropriate lesson.

At the bottom of the importer is a preview window.

When the preview window is open we can

view the changes we have made.

We will need to apply our settings before

the preview window will update it's display.

The preview window will display the image

being imported and report basic information

about the imported texture, including

the size of the imported texture,

the compression setting and the footprint