03/26/2002
15-462 Graphics I
27
Computing Triangle Area
•In 3
dimensions
–Use
cross product
–Parallelogram
formula
–Area(ABC)
= (1/2)|(B – A) £ (C – A)|
–Optimization:
project, use 2D formula
•In 2
dimensions
–Area(x-y-proj(ABC))
=
(1/2)((bx – ax)(cy – ay) – (cx – ax) (by – ay))
A
B
C