Curves and Surfaces
Most common representation for surfaces:
set of connected planar surfaces bounded by polygons
good for boxes, ca
Viewing In 3D
Viewing in 3D
Projection of a 3D object is defined by straight projection rays emanating
from COP (centre of projection) passing through each point of the object
and intersecting the projection plane.
Distance from COP (centre of projection)
What is color?
Color is the spectra of light being perceived by some the human visual
Visible light is EM energy in the 400 to 700 nm in wavelength range of the
What is transformations?
The geometrical changes of an object from a current state to
Why the transformations is needed?
To manipulate the initially created object and to display the
Line Drawing Algorithms
Line Drawing Algorithm
Rasterization: Process of determining which pixels provide the
best approximation to a desired line on the screen.
Scan Conversion: Combination of rasterization and generating
the picture in scan line order
Viewing In 2D
A scene is made up of a collection of objects specified in world coordinates
When we display a scene only those objects within a particular window are
What is a Polygon?
An ordered sequence of three or more edges:
Such that the second endpoint of each edge is the first
endpoint of the next edge.
And the second endpoint of the last edge is the first endpo
Similarly to lines, areas must be clipped to a
Consideration must be taken as to which
portions of the area must be clipped
Polygon Clipping Algorithm
Lots of different cases
Edges of polygon need to be tested against
BASIC ILLUMINATION MODEL
Point source (idealized light)
What should be the color of Q?
Two extreme cases of light reflection:
Light energy in directi