Dear Alexey
Both key points are present in the two chunks I am trying to align before merging, then when I merge the two chunks, I got the error message "Empty pairs list". Metashape creates a merged chunk nonetheless, but the key points disappeared from the second chunk.
I am only interested in having key points in the images of the second chunk, in order to align the new frames to the chunk 1. I don't know exactly the purpose of the Merge Tie Points option? I resumes, frame by frame, the alignment on the chunk 1?
Best regards
Fabrice