I'm imagining some sort of giant feature-based hash table. What does "three oak trees, a light post, and a mailbox in relative positions [data vector]" hash to?

I'm imagining some sort of giant feature-based hash table. What does "three oak trees, a light post, and a mailbox in relative positions [data vector]" hash to? That's an interesting problem. It also has to be some sort of nearest neighbor hash where the same hash without the mailbox component (or with additional preciously untagged components) allowed you to find the same stuff. So I guess this is starting to sound like sparse KNN.