I'm trying to 'blend' a skybox like in a tutorial I'm following, but when I make the material and set the shader to RenderFX/Skybox, it looks different than in the tutorial. In the tutorial there are 12 spots to place skybox images (6 for each skybox) then at the top there is a 'Blend' slider. But on my side, there is only 6 spots and no slider, so I can't blend the skybox like I need to. I'm using Unity free (3.4 I think), is skybox blending only in Pro? Why does it look different?