The Viewing pipeline

The viewing pipeline is a process used in computer graphics to generate a 2D image from a 3D scene. It involves a series of steps that transform the objects in the scene from their 3D coordinate space to a 2D image that can be displayed on a computer screen.

The steps of the viewing pipeline include:

1. Modeling: This step involves defining the 3D objects in the scene, their shapes, positions, and orientations in the world coordinate system. This step can be done using various modeling techniques, such as polygonal modeling, NURBS modeling, or procedural modeling.

2. Viewing: This step involves defining the position and orientation of the camera or observer in the world coordinate system. This is done by specifying the camera's position, target point, and up vector. The camera's position and orientation are used to define the view matrix, which transforms the objects from world space to view space.

3. Projection: This step involves mapping the 3D objects onto a 2D image plane. This is done by applying a projection matrix, which defines the perspective or orthographic projection used to project the objects onto the image plane. Perspective projection mimics the way the human eye perceives depth, while orthographic projection is a parallel projection that preserves the object's size and shape.

4. Clipping: This step involves removing any objects or parts of objects that are outside the view frustum or the area visible through the camera. This is done by applying a clipping plane, which removes any objects that are behind or outside the view frustum.

5. Rasterization: This step involves converting the projected objects into a set of 2D pixels that can be displayed on a computer screen. This is done by mapping the objects onto the 2D image plane, dividing them into small fragments, and assigning a color to each fragment based on its position in the scene and the object's properties, such as its texture, material, and lighting.

6. Display: This final step involves displaying the 2D image on the computer screen. This is done by sending the pixel data to the graphics hardware, which converts it into a signal that can be displayed on the screen.

The viewing pipeline is an essential part of 3D computer graphics and is used in a wide range of applications, such as video games, movies, virtual reality, and computer-aided design.