The nodes of the geometry entity 0 are replaced such that they neatly follow the boundary of geometry 1. In this way, it is easy to make a mesh with elements precisely in specific regions, if this is required to give separate element_group data (e.g. materials) to the geometry and it is too difficult to make the mesh at once ok for this.
Nodes moved in this process automatically get a node_boundary record.
The created mesh may be quite distorted. Consider using control_mesh_remesh.