Normal of a Triangle
–Normal of the plane containing the
triangle (P1, P2 , P3 ):
`n = (P2 - P1) ´ (P3 - P1)
P1
P2
`n
P3
P1
P2
P3
P1
P3
P2
Normal pointing towards you
Normal pointing away from you
•
Models constructed with consistent ordering of triangle vertices :
- all clockwise or all counter-clockwise.
•
Usually normals
point out of the model.