iPhone Transparent

Hello,
I am displaying a 3D Model Edgelib surface.
How do you set Edgelib background to a Transparent see through background? ie not black when calling glClear.
Thanks in Advance
I am displaying a 3D Model Edgelib surface.
How do you set Edgelib background to a Transparent see through background? ie not black when calling glClear.
Thanks in Advance