Viewing Transformations and the Graphics Pipeline

• Object Space
  definition of objects. Also called Modeling space.

  World Space

  where the scene and viewing specification is made

  Eyespace (Normalized Viewing Space)

  where eye point (COP) is at the origin looking down the Z axis.

  3D Image Space

  A 3D Perspected space.

  Dimensions: -1:1 in x & y, 0:1 in Z.

  Where Image space hidden surface algorithms work.

  Screen Space (2D)

  Coordinates 0:width, 0:height

The Computer Graphics Pipeline Viewing Process

Example Image Space Viewing Algorithm Steps

1. Create World Space Scene:
   Position each object (scale, rotate, translate)
   Set up view parameters

   Calculate Backface, illumination, etc.

   Can Perform Backface removal here

   Calculate and Perform World to Eyespace transformation

   Calculate and Perform Perspective Tranformation

   Clip Objects

   Perspective Divide

   Can Perform Backface removal here

   Map to 3D Screen Space

   Viewport Transformation

   Perform Hidden Surface Removal

   Draw to Screen (Scan Convert)

   Shade, texture

Topics to Review

1. 3D Perspective Viewing
2. Backface Removal
3. 3D Sutherland Hodgman
4. Basic Illumination
5. Smooth Shading