The components in the process use either of the mental models. With a typical 3d modeling package, the designer must make the mappings of his mental model to the one understood by the computer, as the data has to be entered as surfaces and coordinates. The same applies also the other way round: the dull and clean surfaces of the rendering need to be interpreted as something more vague and unfinished. This burdain of making the mappings practically destroys the flow of visual information essential for sketching.

Therefore, research in sketch based modeling has tried to move that burdain to the computer. The problem has been approached from two directions: first, by making the input more natural with pen-based interfaces and other innovations, and second, by using non-photorealistic rendering techniques. This indeed has improved the situation, now the input and output are closer to the mental model of the designer.