Lecture Computer graphics: Lecture 24 - Fasih ur Rehman

You are introduced to various pointing devices, such as the mouse, trackball, touchpad, pointing stick, joystick, touchscreen, and pen input. Scanners and reading devices, including optical scanners, optical readers, magnetic ink character recognition readers, and data collection devices are explained,...

Trang 1

Computer Graphics

Lecture 24

Trang 2

Last Class

Trang 3

Today’s Agenda

Trang 4

Light, Surface and Imaging

Trang 5

* Shading

Trang 6

Specular Surfaces

- Specular surfaces appear shiny because most of the light that is reflected or

scattered Is in a narrow range of angles close to the angle of reflection

Trang 7

Diffusive Surfaces

- Diffuse surfaces are characterized by reflected light being scattered tn all

directions Walls painted with matte or flat paint are diffuse reflectors

Trang 8

Translucent Surfaces

- Translucent surfaces allow some light to penetrate the surface and to emerge from another location on the object

- This process of refraction characterizes glass and water

Trang 10

Light Sources

-_ Color Sources “|

Amblent Light (uniform lighting)

PoInt Source (emits light equally ¡n all directions)

Trang 11

What Shading can do?

Trang 12

- and uses four vectors

Phong Reflection Model

Trang 13

Summary

Trang 14

References

‘ Fundamentals of Computer Graphics Third Edition by Peter Shirley and Steve

Marschner

* Interactive Computer Graphics, A Top- down Approach with OpenGL (Sixth