Global Mapper v25.0

Basic question-how to delineate area to generate elevational mesh

Blooper
Blooper Global Mapper User
edited July 2015 in How I use Global Mapper
I've just started using Global Mapper 15 and needed a pointer. I'm trying to generate terrain meshes from a wide area, I'm using SRTM Worldwide Elevation Data and have loaded it up fine but my initial mesh was 400mb which is too big for me to import easily to 3Ds Max. Problem is, when I draw a selection box or zoom into an area it always outputs a mesh that's 400mb in size. I can't seem to select a smaller area to export, can anyone explain how I go about doing this?