Oooh, I'm sorry for the misunderstanding, I was talking about the texture files that make up the ground:
data/texture/chessboard05.bmp
data/texture/chessboard01.bmp
data/texture/chessboard02.bmp
data/texture/chessboard03.bmp
data/texture/chessboard04.bmp
data/texture/chessboard9.bmp