You can do simple and complex 3d reliefs if you watch the video lesson in "Creation a bas-relief from 3d scenes". This video is available on the website http://buy.3drelief.net

Demo:
http://www.youtube.com/watch?v=ZXPn2PF_Wy4&feature=g-upl&context=G2b1e791AUAAAAAAADAA
http://www.youtube.com/watch?v=k9_wtEsZBQ0&feature=g-upl&context=G2f9be6dAUAAAAAAACAA
http://www.youtube.com/watch?v=L5sffEExPU4&feature=g-upl&context=G274db0cAUAAAAAAAAAA

Blog:
http://3d-relief.blogspot.com/2012/03/video-tutorials.html