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Matrix routines

   

Because matrices are rather large when expressed in text form, the following definitions are used for the examples.

        Using it correctly calls for understanding how it works internally. There are three matrices: centering, rotation, and offset. The centering matrix determines where the center of rotation is located. By default, this is the origin, but it can be changed to pivot about any point. The rotation matrix defines the rotation about that centering point, and the offset matrix defines the final translation after the rotation.

For example, to rotate around a given point, the transformations would be 1) the centering matrix to bring that point to the origin, 2) the rotation about the center, and 3) the final offset to return the origin back to its original location.

The different options for the trans command modify the matrices in various ways.

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next up previous contents index
Next: Multiplying vectors and matrices Up: Vectors and Matrices Previous: Vectors

Justin Gullingsrud
Tue Apr 6 09:22:39 CDT 1999