PROJECTIONS

Once world-coordinate descriptions of the objects in an exceedingly scene are converted to viewing coordinates, we will project the three-dimensional objects onto the trio- dimensional view plane.

There are two basic projection methods.
1. Parallel Projection
2. Perspective Projection

In a parallel projection, coordinate positions are transformed to the viewed plane along parallel lines

For a perspective projection, object positions are transformed to the view plane along lines that con- verge to a degree called the projection reference (or center of projection). The projected view of an object is decided calculation~ the interjection of the projection lines with the view plane.