Page 186 - Computer Graphics Handout

4.10.1 Window-to-Viewport Mapping
A window represents a selected region of the world-coordinate scene, while a viewport defines the corresponding region on the
display device. Window-to-viewport mapping transforms coordinates from the window to the viewport through scaling and
translation operations.
This mapping preserves relative positions of objects and allows graphical scenes to be displayed on different screen sizes and
resolutions without distortion.

4.10.2 Normalized Device Coordinates
Normalized Device Coordinates (NDC) provide a device-independent representation of graphical objects. After applying viewing
and projection transformations, coordinates are normalized to a standard range, typically between 0 and 1 or −1 and 1.
The use of normalized device coordinates simplifies the graphics pipeline by enabling consistent processing across different display
devices and resolutions.

4.10.3 World-to-View Transformations
World-to-view transformations convert object coordinates from the world coordinate system to the view (or camera) coordinate
system. This transformation positions and orients the camera within the scene, determining how objects are observed from a
particular viewpoint.
These transformations are fundamental to viewing operations and form the basis for subsequent projection and clipping processes.

4.11 Rendering and Ray Tracing

Rendering is the process of generating a two-dimensional image from a three-dimensional scene description. It involves
transforming geometric data, applying lighting models, and determining visible surfaces. This section introduces the basic concepts
of rendering and the fundamentals of ray tracing.

4.11.1 Shading Models
Shading models describe how light interacts with surfaces to determine their final appearance. Common shading approaches include
flat shading, Gouraud shading, and Phong shading, each offering different levels of visual realism and computational complexity.
Shading models play a critical role in enhancing depth perception and surface detail in rendered images.

4.11.2 Rendering Pipeline
The rendering pipeline consists of a sequence of stages that process graphical data, including transformation, lighting, clipping,
rasterization, and shading. Each stage contributes to converting a scene description into a final image suitable for display.
Modern graphics systems implement the rendering pipeline using programmable hardware to achieve high performance and
flexibility.

4.11.3 Ray Tracing Fundamentals
Ray tracing is a rendering technique that simulates the physical behavior of light by tracing rays from the viewer through the scene.
Rays interact with objects through reflection, refraction, and shadow generation.
Although computationally intensive, ray tracing produces highly realistic images and is widely used in advanced graphics applications
and visual simulations.

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