If you wish to post the question on Math.SE then try to reduce your original problem into something more suitable for the community. For example, Calculate Rotation Matrix to align Vector A to Vector B in 3d?
I have one triangle in 3d space that I am tracking in a simulation. Between time steps I have the the previous normal of the triangle and the current normal of the triangle along with both the current and previous 3d vertex positions of the triangles.
Using the normals of the triangular plane I would like to determine a rotation matrix that would align the normals of the triangles thereby setting the two triangles parallel to each other. I would then like to use a translation matrix to map the previous onto the current, however this is not my main concern right now.
I have found this website http://forums.cgsociety.org/archive/index.php/t-741227.html
that says I must
- determine the cross product of these two vectors (to determine a rotation axis)
- determine the dot product ( to find rotation angle)
- build quaternion (not sure what this means)
- the transformation matrix is the quaternion as a 3 by 3 ( not sure)
If your question requires a lot of time and effort to answer, consider awarding a bounty.
Alternatively, there is a Game development Stackexchange which has mathematics and 3d tags. Weapon of choice mentions Blender Stackexchange (which is currently is beta).