Perspective projections are also called central projections and are one technique for showing a three-dimensional object on a flat surface. They are called perspective drawings or "pers" for short. Because they enable the creator to produce an identi

Section diagrams are auxiliary diagrams showing parts that are not visible. Invisible parts in a three dimensional object are shown by hidden outlines (broken lines) but if too many are used, the blueprint becomes complicated and difficult to read. T

Projection methods are broadly divided into perspective and parallel projection. Projection is a means of representing a three-dimensional object in two dimensions and orthographic projection is a form of parallel projection. A feature of orthographi