How to convert a 3x3 rotation matrix into 4x4 matrix?

Question

I\'m currently using a 3x3 rotation matrix to work with 3D points.

How does this matrix differ from a 4x4 Matrix?

And how do I convert a 3x3 matrix into a 4x

Answer 1

A 4x4 matrix will support all affine transforms, including rotation and translation.

See the answer to this question: Solution to skew bitmaps in flash

For the gory math, see: http://www.euclideanspace.com/maths/geometry/affine/matrix4x4/index.htm