Control a GUITexture's material?

[system]

I'm trying to make a circular progress bar like this and my problem is assigning the material to the GUITexture. I created a material with the alpha cutoff shader, but I don't see how I can apply it to the GUITexture that will be rendered. Does anyone have any ideas?

[Eric5h5]

You can't change a GUITexture's material. You'd use quads, created in a 3D app (or this).