I don't remember all the details of displacement now. I'd suggest you set up some small test cases to see. But I don't think you can have different material on different sides of the face. certainly not different displacements. Face normals matters greatly with displacement. (how the faces are oriented. You should verify that all your face normals are oriented properly - the front (default SU colour white) should be pointing outwards.) In general you should always have full control over your face normals, especially when rendering. Now and then, switch the SU style to display the faces in SU's default colours, you might even set the backside colour to a bright colour to make it easier to spot faces oriented incorrectly.

Unusually the first thing to test is the graphic card - as it's the cause in 90% + of the cases.

@thomthom said: That is just a link for yourself. Refer to these page on how to share Dropbox files: https://www.dropbox.com/help/16 https://www.dropbox.com/help/167 hello just to check if links are working.. let me know, thanks!