World/Level Building Tools

Hey everyone,
Basicly if you have a flat cavas with the landscape and you start sculpting away, how would you masure scale or if the player can even get from A to B and how long it would take?
To be clear, There’s another materal about auto materials out there, I’m specifically talking about the scale of the world and how to manage it, if that makes sence

I was thinking of looking at how the Nav mesh/Path finding works to see if i can solustion that way

if you have any tool, soulatiuons or methods of approch, that will be great full

Thanks