I would like to make
the following additions to the page.
First of all, I would like to state that the plane's orientational vector
should be a normal if it is to be used in the projection matrix equation:
projection matrix = [I] - v * vt
v should be the plane's normal.
Further more I would like to add that a plane can also be described by
it's two edge vectors. The vector describing it's orientation is then
simply the cross product of those two vectors.
This information might not add new information, since it can be distilled
from the page as it is. However, it would have been very useful for me
(a beginner) if I would have known about this. I ran into a problem because
I used orientation vectors that weren't normals :(.
Where I can, I have put links to Amazon for books that are relevant to
the subject, click on the appropriate country flag to get more details
of the book or to buy it from them.
New Foundations for Classical Mechanics (Fundamental Theories of Physics). This
is very good on the geometric interpretation of this algebra. It has lots of insights
into the mechanics of solid bodies. I still cant work out if the position, velocity,
etc. of solid bodies can be represented by a 3D multivector or if 4 or 5D multivectors
are required to represent translation and rotation.