Answer by Edy

You can specify the the opacity of a texture by setting each pixel's alpha value. However this is quite slow for fading animations (requires many [SetPixel][1] calls), so you'd better use a regular _Plane_ (GameObject > Create other > Plane) in front of the camera showing the texture. You can change the transparency by setting the Alpha value for the base color (ensure to use a transparent material). [1]: http://unity3d.com/support/documentation/ScriptReference/Texture2D.SetPixel.html