Introduction to Computer Graphics and Rendering Techniques

Computer Graphics

Field of creating images using computers.

Raster-Scan Displays

Displays images as discrete points called pixels.

Scan-Line

Each row of pixels in a raster display.

Frame Buffer

Buffer storing pixel information and attributes.

Refresh Rate

Frequency of screen picture redisplay.

Vertical Synchronization (Vsync)

Synchronizes frame rate with display refresh rate.

Screen Tearing

Display shows parts of multiple frames simultaneously.

Graphics Pipeline

Stages transforming vertex data into display pixels.

Modeling Transformations

Transforms geometric models into different representations.

OpenGL

Graphics rendering API using a programmable pipeline.

Shaders

Programs controlling stages of the rendering pipeline.

Vertex Shaders

Process individual vertices in the graphics pipeline.

Fragment Shaders

Process individual fragments, potential pixels.

GL_POINTS

OpenGL primitive representing individual points.

Convex Polygon

All interior angles less than 180 degrees.

Concave Polygon

At least one interior angle greater than 180 degrees.

Vertex Buffer Object (VBO)

Stores vertex data like coordinates and colors.

Vertex Array Object (VAO)

Stores state needed for supplying vertex data.

Uniform Variables

Constant values passed to shaders for all vertices.

Attribute Variables

Per-vertex data like position and color.

Varying Variables

Pass data from vertex shader to fragment shader.

Dot Product

Measures cosine of angle between two vectors.

Cross Product

Produces a perpendicular vector in 3D space.

Identity Matrix

Diagonal elements are 1; others are 0.

Homogeneous Coordinates

Extra dimension to represent points and vectors.

Translation

Moves an object by specified distance in 2D.

Scaling

Enlarges or shrinks an object by a factor.

Rotation

Rotates an object around a pivot point.

GLM

C++ library for vector and matrix operations.

Perspective Projection

Simulates objects appearing smaller with distance.

View Frustum

Truncated pyramid defining visible 3D region.

Point Source Light

Emits light equally in all directions.

Phong Reflection Model

Calculates color based on ambient, diffuse, specular.

Flat Shading

Single color per polygon, faceted appearance.

Gouraud Shading

Interpolates vertex colors for smooth transitions.

Phong Shading

Calculates lighting per fragment for highlights.

Mach Bands

Visual illusion enhancing contrast between adjacent polygons.

Non-photorealistic Rendering (NPR)

Techniques for achieving artistic rather than realistic visuals.

Toon Shading

A non-photorealistic rendering technique creating cartoon-like visuals.

Texture Mapping

Applying images to surfaces for enhanced visual detail.

Texture Coordinates

(s, t) values mapping surface points to texture images.

Texture Wrapping

Defines handling of texture coordinates outside 0.0 to 1.0.

Texture Filtering

Techniques managing size differences between texels and pixels.

Mipmaps

Lower-resolution texture versions for efficient distant viewing.

Multi-texturing

Applying multiple textures to a single surface.

Normal Mapping

Uses textures to modify surface normals for detail illusion.

Environment Mapping

Simulates reflections using surrounding environment images.

Color Buffer

Stores color values for each pixel in rendering.

Double Buffering

Uses front and back buffers to prevent flickering.

Depth Buffer (Z-Buffer)

Stores depth values to determine visible surfaces.

Stencil Buffer

General-purpose buffer for effects like masking and shadows.

Blending Equation

Determines combination of source and destination colors.

Back-face Culling

Discards polygons facing away from the camera.

Depth-Sort Method

Renders polygons from back to front for visibility.

Clipping

Removes object parts outside the view frustum.

Cohen-Sutherland Line Clipping

Efficiently clips lines against rectangular clipping window.

Hodgman-Sutherland Polygon Clipping

Clips polygons against a rectangular clipping window.

Weiler-Atherton Polygon Clipping

Handles concave polygons and clipping regions efficiently.

DDA Algorithm

Uses floating-point calculations for pixel positions.

Bresenham's Line Algorithm

Efficiently approximates lines using integer calculations.

Scan-line Polygon Fill

Fills polygon interiors based on edge intersections.

Ambient Light

A type of light that provides uniform illumination throughout a scene, simulating indirect lighting.

Attenuation

The decrease in light intensity with distance from a light source.

Blending

Combining multiple images or layers into a final composite image.

Coordinate Systems

Different reference frames used to represent the position of objects in a scene, such as world coordinates, view coordinates, and screen coordinates.

Diffuse Reflection

The scattering of light in all directions from a surface.

Directional Light

A light source that emits parallel rays of light, simulating a distant light source like the sun.

Fragment Shader

A program that runs on the GPU and processes individual fragments (potential pixels), determining their colors.

Hierarchical Model

A complex object composed of multiple parts, each with its own transformations, organized in a parent-child hierarchy.

Interpolation

The process of smoothly transitioning between values, such as colors or normals, across a surface.

Light

Electromagnetic radiation that interacts with objects, creating color and shading.

Line Clipping

The process of removing portions of lines that fall outside the clipping window.

Matrix

A rectangular grid of numbers arranged in rows and columns, used for representing transformations in computer graphics.

Normal Vector

A vector perpendicular to a surface at a given point, used for lighting calculations.

Pixel

The smallest unit of a digital image, represented as a single point with color and other attributes.

Point Light

A light source that emits light equally in all directions from a single point.

Polygon Clipping

The process of removing portions of polygons that fall outside the clipping region.

Polygon Fill Algorithms

Algorithms used for filling the interior of a polygon with a specific color.

Rasterization

The process of converting geometric primitives, such as lines and polygons, into pixels on the screen.

Reflection Mapping

See environment mapping.

Shader

A program executed on the GPU that controls various stages of the rendering pipeline.

Specular Reflection

The reflection of light in a specific direction, creating highlights.

Spotlight

A light source that emits a conical beam of light.

Transformation Matrix

A matrix used to represent transformations, such as translation, rotation, and scaling.

Vector

A mathematical entity with magnitude and direction, often used to represent positions, directions, and displacements in computer graphics.

Vertex Shader

A program that runs on the GPU and processes individual vertices, determining their positions and other attributes.

Viewing Transformation

The transformation from world coordinates to view coordinates, defining the camera's position and orientation in the world.

Viewport Transformation

The transformation that maps the projected 3D scene onto a 2D viewport on the screen.

Visibility Determination

Techniques for determining which objects are visible and should be rendered.

Vsync

Vertical synchronization, a technique that synchronizes the graphics frame rate and display refresh rate to prevent screen tearing.

World Coordinates

A coordinate system that defines the global position of objects in a scene.