HA7 - Task 2 - Displaying 3D Polygon Animations

API

API stands for an application programming interface. This involves a set of tools for building software applications. An API includes a set of programming instructions for accessing a web based softare application. A software company will release its API to the public so that the other software developers can design products. 

Example API
For example, Amazon.com released its API so that Web site developers could more easily access Amazon's product information. Using the Amazon API, a third party Web site can post direct links to Amazon products with updated prices and an option to "buy now."

Graphics Pipeline

One of the key developments in computer graphics has been the evolution of the GPU from a fixed pipeline to a programmable pipeline. The means various stages of the pipeline can be programmed, using programs called shaders.

Stages of The Graphics Pipeline

3D Geometric Primitives

Geometric primitives are the simplest objects which the system can handle. These primitives are what the scene is initially made up of. 

Modelling and Transformation

This is when you transform something from the local coordinate system and change it to the 3D coordinate system. 

Camera Transformation

This is when you transform something from the 3d coordinate system and change it to the camera coordinate system. You must ensure that the camera is the origin. 

Lighting

Using lighting and reflectance is important to make your object seen. For example: a light coloured object in a dark environment will not be seen unless the lights are adjusted correctly. 

Projection Transformation

3D projection is taking three dimensional points and changing them to two dimensional. Perspective projection is when objects which are far away from the camera are made smaller. This is done by splitting the X and Y coordinates of each primitive by the Z coordinate. Where as orthographic projection stay at their original size no matter where they are in relation to the camera. 

Clipping

Any primitives which appear outside of the viewing frustrum will now not be visible.

Scan Conversion or Rasterization 

Rasterization is when the 2D image becomes converted into the raster format and the final pixel values are created. This means that any future edits will be determined on each separate pixels. 

Texturing, Fragment Shading

At this point in the pipeline each individual fragment is assigned a colour. These colours can be selected from a shading program or texturing. 

Sources

http://en.wikipedia.org/wiki/Application_programming_interface

http://money.howstuffworks.com/business-communications/how-to-leverage-an-api-for-conferencing1.htm

http://media.corporate-ir.net/media_files/IROL/97/97664/images/amazon_logo_RGB.jpg
http://goanna.cs.rmit.edu.au/~gl/teaching/rtr&3dgp/notes/pipeline.html 
http://www.shaveenk.com/wp-content/uploads/2013/01/graphics_pipeline.jpg 

http://en.wikipedia.org/wiki/Geometric_primitive

https://cshusteridd410.files.wordpress.com/2009/10/geo_primitives1.jpg

http://isg.cs.tcd.ie/spheretree/pics/teapot.gif

http://www.fundza.com/rib/example4/illust_6.png

https://developer.apple.com/library/safari/documentation/InternetWeb/Conceptual/SafariVisualEffectsProgGuide/Art/3d_axes.jpg

http://what-when-how.com/wp-content/uploads/2012/07/tmp863b133_thumb.png

http://sabia.tic.udc.es/gc/Contenidos%20adicionales/trabajos/Opengl/camara_Ogl/imagenes/image017.jpg

http://techpubs.sgi.com/library/dynaweb_docs/0650/SGI_Developer/books/Perf_GetStarted/sgi_html/figures/aspect.ratio.gif

http://media.mediatemple.netdna-cdn.com/wp-content/uploads/2012/02/rasterization-strategies.png

http://www.visualizationlibrary.org/documentation/pics/pagGuideGLSL.jpg