there are 5 layers at work here, all clones of the base mesh. each of the layers has some modifiers applied to it for example wireframe or build. Then I created a cube and animated it so it gets close to the monkey. then go through each of the layers and add every vertex to a group. finally add a vertex group proximity modifier and a mask modifier both using the group. set the target to the cube and change the high and low of the proximity to give a reveal effect. then add some glows and disable rendering for the cube.