How the two pictures blend together?

I know that ODM uses the SIFT algorithm to get image features and the FLANN algorithm to do feature matching.

But I have a question: if two images match together, how does ODM handle overlapping areas?

Can someone show me where this code is located?

mvs-texturing is the library we use. You can find an overview and all the relevant papers here: https://www.gcc.tu-darmstadt.de/home/proj/texrecon/