"Stitching" two meshes

Hello,

I have two meshes. The grey mesh is a Digital Terrain Model and the green mesh is modelled manually using more accurate survey data. I would like to stitch these two meshes together, so I don’t have large visible holes in my final model which will be used in Twinmotion for rendering.

The command Stitch in R7 doesn’t work and gives this error - Invalid input for Stitch: Invalid selection count.

I would like to keep the green mesh unedited. Essentially, what I’m trying to achieve is to pull the edge vertices of the grey mesh to the closest point of the edge of the green mesh. They don’t need to be welded and tiny gaps are ok. Any suggestions?

Maybe you can use a _MeshPatch between the 2 boundaries ?
Make sure there is a continous gap along the 2 meshes you want to join.