I am referring to the paper here, section 2.6.1, on the adding and subtracting of two TINs:
The addition of two TINs can be determined exactly and stored into a new TIN, because the addition of piecewise linear functions again yields a piecewise linear function. The addition is done by performing an overlay of
T2, there are several algorithms for this. After this we obtain a subdivision where all faces have 3,4,5,6 edges. We now must fill in the height information for the vertices of the overlay..
Although I can understand every single word out of the passage, I don't know how to carry out the above procedure in practice to obtain the cut/fill of the two TINs.
More specifically, I would like to know how to perform the overlay of two TINs. There are references given at the end of the paper, but I can't have access to them because I'm not inside a university library. So any readily accessible online reference (or code samples) are greatly appreciated!