[Hill: 217-222.
Foley & van Dam: p. 201-208, 213-217]
Derivation of Transformations
translation |
|
scaling |
|
shear |
|
rotation |
|
Note: A positive rotation about the z-axis is defined as one
that rotates from the positive x-axis to the postive y-axis. We can similarly
define rotations about the other two axes. These definitions hold for both
RHCS and LHCS.
-
about x-axis: positive y to positive z
-
about y-axis: positive z to positive x
-
about z-axis: positive x to positive y
Transformation Matrices
The transformations defined above can be rewritten using 4x4 matrices and
homogeneous coordinates. The general form of the matrix is:
The expressions derived earlier correspond to the following transformation
matrices.