Computer GraphicsComputer Graphics

Sohaib A KhanSohaib A Khan

CS101 Wk02 Topical LectureCS101 Wk02 Topical Lecture

Some Key ConceptsSome Key Concepts

The Graphics PipelineThe Graphics Pipeline Physical ModelsPhysical Models Real-time vs Non-real-time graphicsReal-time vs Non-real-time graphics AnimationAnimation Non-Photorealistic RenderingNon-Photorealistic Rendering Image Based RenderingImage Based Rendering

Object RenderingObject Rendering

Modeling:Modeling:– How to represent How to represent

objectsobjects RenderingRendering

– How to create How to create imagesimages

AnimationAnimation– How to represent How to represent

motionmotion

ModelingModeling

RenderingRendering

Compute camera Compute camera viewview

ClippingClipping Hidden line Hidden line

removalremoval

Image Credit: Cornell University Program of Computer Graphics

RenderingRendering

ShadingShading LightingLighting Shadows?Shadows? Converting 3D to Converting 3D to

2D2D

Image Credit: Cornell University Program of Computer Graphics

AnimationAnimation

Copyright: ACM SIGGRAPH 2000Physically Based Modeling

Animation in MoviesAnimation in Movies

Two Key Techniques for Animation

1. Motion Capture2. Key Framing Physical Modeling of

Motion is very difficult

http://cgw.pennnet.com/Articles/Article_Display.cfm?Section=Archives&Subsection=Display&ARTICLE_ID=108473&KEYWORD=Final%20Fantasy

Tom Hanks"I am very troubled by it. But it's coming down, man. It's going to happen. And I'm not sure what actors can do about it" (8 July 01)

http://www.popmatters.com/film/reviews/f/final-fantasy.html

Making a Computer GameMaking a Computer Game

Two distinct tasks are involvedTwo distinct tasks are involved

1.1. The Graphics EngineThe Graphics Engine

2.2. Artwork, both in 3D and 2DArtwork, both in 3D and 2D

Real-Time GraphicsReal-Time Graphics

http://www.nrich.maths.org.uk/mathsf/journalf/may00/art3/

Off-line (Non-RealTime) Off-line (Non-RealTime) RenderingRendering

Image Credit: 2001 Internet Ray Tracing Competition – N. Kern

Non-Photorealistic RenderingNon-Photorealistic Rendering

Image Based RenderingImage Based Rendering

Instead of building models bottom-Instead of building models bottom-up, use images to render new scenesup, use images to render new scenes

If an image of a scene is captured If an image of a scene is captured from one angle, how would the scene from one angle, how would the scene look like from a slightly different look like from a slightly different angle?angle?