Computer Graphics
At a high level, computer graphics [see page 8, differs] from
- Computer Vision - understanding what is being seen, classifying objects.
- Image Processing - identify characteristics or ways to better present important features of an image.
Computer Graphics is more taking a description of a scene and producing an image for it.
Uses:
- Training and Testing
- Designing
- Understanding through scientific visualisation
- Enhancing the existing world (augmented reality)
- Entertainment/Pleasure
Real
In CG we have to do:
- Geometric Modelling - define and arrange a set of objects in a scene
- Position a Synthetic Camera
- Define The Lighting - Where the lights come from
- Calculate Lighting - for every object
- Convert 3D scene into a 2D View
- Animate any non-static Objects (at least 30fps)
We're gonna need a tonne of [see page 15, maths].
Modelling
Geometrically describe something in the real world.
Kinds of representations:
- Polygons
- Patches - Curvy Linear Polygons
- Constructive Solid Geometry
- Implicit Surfaces
- Procedural Approaches
- Space Subdivision
We call the area in which a model is arranged a scene graph.
Hirarchical Objects
Parts of the object moves relative to the other, eg. joints in a skeleton.
Material Properties
- Colors
- Textures
Transformations
- Rotation
- Scale
- Translation
Can all be represented as matrices and bulk applied to a model.
Rendering
Converting a 3D world model into a 2D view thoguh a perspective projection. This involves calculating lumination, textures, shadowing etc.
Part of this involves:
- Hidden Surface Removal - decide which objects can be seen.
Animation
Update parts of a scene: eg. hirearchy, position, color, orientation.