Oblique Projection: Projecton Chart of One-Way Extension

Oblique projection is a parallel projection where projectors are inclined or oblique to the plane of projection. It can be said that oblique projection is obtained when the plane of orthogonal projection is rotated. Therefore, the oblique projection can be produced by one-way uniform extension of a orthographic projection.In this paper, we show that scale of oblique projection can be represented by a ratio and a direction of the extension. We also explain the complete conditions of the extension to obtain frontal axonometries.