I’m very new to blender and I was working with a scene a friend gave me. It was a plain grass field and with some heavy tweaking and modification I made this dike and ditch. However the right bank of the ditch appears to be receiving some kind of checkerboard shadows which I can’t explain or fix. Can anyone help?
*Here is the blend file: https://docs.google.com/file/d/0B9rcAu5N0H7KbDFkdk9Gcm12V28/edit