Positive space refers to the subject or areas of interest in an artwork, such as a person's face or figure in a portrait, the objects in a still life painting, or the trees in a landscape painting. Negative space is the background or the area that surrounds the subject of the work.
When drawing the best thing to do is to create the 2D picture ten create the 3D image meaning it starts off as 2D because the artist has to understand 2D first.