Sculpture is the branch of the visual arts that operates in three dimensions. It is one of the visual arts. Durable sculptural processes originally used carving (the removal of material) and modelling (the addition of material, such as clay), in stone, metal, ceramics, wood and other materials but, since Modernism, there has been an almost total freedom of materials and processes. A wide variety of materials can be worked by extraction, such as carving, assembled by welding or modelling, or moulded or cast.