matrix_world

This multiplies the coordinates as found in the object data with the world matrix of that object. Essentially giving the world coordinate of any selected vertex, even when the object origin is not at the world origin.

Further reading

• http://db-in.com/blog/2011/04/cameras-on-opengl-es-2-x/

Place empty while in Edit Mode

Sometimes we need to place a marker (Empty) at a given point on our mesh. I use this often to define a pivot point. But manually hopping in and out of edit mode to add an Empty soon becomes lame. This is my solution. Run this in edit mode, select as many verts as you wish.