What tool can make a nice 3D image of a via?
You can zoom into your board in the 3D view in Altium:



I changed the view settings to scale up the board thickness (otherwise you can't get a good look inside) and to color the structures by layer.



To remove copper from un-used layers like so:


In 2D layout mode, open the via properties and select "Full-Stack" in the Diameters panel:
 

Set the diameter to 0 for desired layer: