Efficient shape creation between nodes

I'm making a game where players place and grow "nodes" to form "territories".

Nodes create connections with other nodes based on their size and proximity (larger nodes reach out further)

I need to create a mesh from the edges of the territory.

My problem is in finding the boundaries of the territory efficiently, so I'm not creating a mesh between every node, and instead only creating edges between the outermost nodes.

I'm totally at a loss for any suitable algorithms which might exist - is this fundamentally a travelling salesman problem?

Thanks in advance everyone!