i need to constrain an object to follow a single part on a mesh. like a button on a shirt. Ive tried hooks, that just constrains vertices to an objects. i need the objects to follow vertices as they are being deformed by an armature 
if anyone can help it would be much appreciated.
Vertex parent ?
Select the child, shift select the parent object, tab into edit mode, select the vertex you want to parent to and Ctrl+P
-face palms-… .your kidding it was that easy… when i saw that someone developed a script for what i need to do i assumed it wasn’t possible so i was looking for a work around XD lol (the script didn’t work. so i guess it was for an older version of blender) anyways thank you ^.^