2.Introduction to image synthesis Flashcards
The user moves the mouse, where does opengl fit in?
Input device -> OpenGLAPI->App program->App model (and then back again ending in display)
What can a vector based display draw?
Lines, text and points
In a graphics pipeline what is a fragment?
A candidate pixel which may or may not be displayed
What is the fundamental difference between a fixed and a programmable pipeline?
In a programmable pipeline the user has to program some parts themselves (SHADERS)
Which statement best describes OpenGL?
An API for doing 3D computer graphics
What dimension of matrix does opengl use for 3d transformations?
4x4
Who oversees the development of OpenGL?
Khronos
Name 7 features of OpenGL
- 3D Graphics
- Coordinate Transformations
- Viewing “camera”
- Hidden Surface Removal
- Lighting & Shading
- Texturing
- Pixel (image) operations
Name the support libraries of OpenGL
GLU & GLUT
The graphics pipeline flows from ____ to _____
Application’s 3D vertices —->pixels
Last two stages (of 5) in the graphics pipeline
4.RASTERIZATION (scan conversion):
Primitives -> Fragments
5.FRAGMENT OPERATIONS (blending, depth test)
Fragments -> Pixels
First two stages (/5) in the graphics pipeline
- Transformations & viewing
2. Lighting (Gouraud/Phong)
Middle stage of the graphics pipeline
3.Primitive assembly (clipping)
Name the two types of shader in the programmable pipeline that must be provided
Vertex shader and fragment shader
Algorithm to scan convert a line?
Bresenham’s algorithm
How does Bresenham’s algorithm scan convert a line?
Approximate with newarest available pixels
What algorithm to scan convert a polygon?
Sweepline algorithm
Data structure of hidden surface removal? What does it store?
Z-buffer (stores pixel z-depth)
What’s a problem that can happen when numbers in z-buffer aren’t precise enough?
Z-fighting or stiching
What are raster graphics?
A raster graphics or bitmap image is a DOT MATRIX DATA STRUCTURE that represent a rectangular grid of pixels stored in an IMAGE FILE
When working with a fixed pipeline what does the programmers application provide through the API?
PARAMETER CHANGES
