How to show the section plane of a object

i want to show the section plane of a 3D object.
I set LookAt(0.0,0.0,8.0,0.0,0.0,0.0,0.0,1.0,0.0).
at the same time i use glClipPlane(GL_CLIP_PLANE1,eq); the eq={0.0,0.0,1.0,0.0}.but the back half is cut off. maybe it function glClipPlane cann’t do what i want.
So how to show the section plane of a object? i think other method should be used.

anyone who knows?
Help me.

You have cross-posted this question on the advanced section too; please don’t cross-post.