Material.GetTexture  

function GetTexture (propertyName : String) : Texture

Description

Get a named texture.

Many shaders use more than one texture. Use GetTexture to get the propertyName texture.

Common texture names used by Unity's builtin shaders:
"_MainTex" is the main diffuse texture. This can also be accessed via mainTexture property.
"_BumpMap" is the normal map.
"_Cube" is the reflection cubemap.

See Also: mainTexture property, SetTexture.

function Start () {
    var tex : Texture = renderer.material.GetTexture ("_BumpMap");
    if (tex)
        print ("My bumpmap is " + tex.name);
    else
        print ("I have no bumpmap!");
}