matrix problem

i’ve got a trnasformation matrix and i’ve got coordinates of vetex after that matrix has been applied on it. is it possible to doetermine original vertex coordinates?

v’ = Mv
v = M^-1 * M * v

If your transformation matrix is non-singular(determinant != 0) then yes. Determining the inverse can be difficult though. It all depends what you start out with…

I think the above should be:

u - initial position
v - final position

v = M * u
u = M^-1 * v

Determining the inverse of a matrix is a rather complicated process. Try to google it and look for the formula based on Cramer’s rule. Keep in mind that calculating the inverse of a matrix is really computationally expensive and so you don’t want to do it too often.

yeah, everything works cool… all needed inverse matrices are computed during initialization so ist’s pretty fast