Oblique projection: It is generated by projecting points across parallel lines that are not perpendicular to the projection plane. Here normal to the view plane direction and direction of projection are different. It is of two types: cavalier and cabinet.
Cavalier projection: Here direction of projection makes 45 degrees angle with view plane and the projection of a line perpendicular to view plane has same length as the line.
Cabinet projection: Here direction of projection makes 63.4 degrees angle with view plane and the projection and lines perpendicular to viewing surface are projected at one half their actual length.