Mesh extraction is a fast and powerful way to create new parts to your model. Using existing geometry you can quickly and easily create a jacket, a helmet, gloves, whatever your character may need! Mesh Extractions works by isolating parts of one model and, in a sense, duplicating that as another mesh. It also 'cleans' the edge of the extracted mesh to create a smooth, even boundary. Just paint a selection on the area you want new geometry to be created from and simply extract!