The window defined in world coordinates is first transformed into normalized device coordinates. The normalized window is then transformed into the viewport coordinate. This window to viewport coordinate transformation is known as workstation transformation. It is achieved by performing following steps:
1. The object together with its window is translated until the lower left corner of the window is at the origin.
2. Object and window are scaled until the window has the dimensions of the viewport.
3. Translate the viewport to its correct position on the screen.