Using same file from T74195:
- Open the file
- Set curve precision to 15 and increment the value further.
- Notice how incrementally bigger and bigger chunks of the geometry get merged together.
Think there are two issues there:
- Merge threshold seems to be a constant, non-editable value currently. It should either be exposed to user (as many other places in Blender), and/or made "smart" by adjusting its value to the global size of the geometry (using eg the farthest vertex from origin, or something like that).
- Merge algorithm itself looks somewhat broken, as it seems to merge more and more geometry, leading to serious loss of details when the vertex density gets high.
Note: noticed while reviewing D7214.