This script has been in my toolbox for a long time, so I’ve taken it out, polished it up, and partnered it with a friend. There are probably other scripts out there that will do this for you but I hope you will find mine intuitive and easy to use.
This tool will align an object to a plane defined by three points.
Pick your source objects, activate the tool and then click the three
points. Max refuses to show the snap icon after the first click but it
will snap correctly.
This tool will align an object to the edge of another, or it will create a dummy along the edge of another.
Pick your target object, select an edge in the sub-object and then
activate the tool. Now either click your source object or right click to
have a dummy created along that edge.
Download the mzp package and drop it into your max viewport.
customize | customize user interface
choose the JNScripts category and the two tools should be
listed. Drag them onto a toolbar. You may need to re-start Max in order
to get the icons to show correctly.
If I can think of any more then I will expand the toolbox. Requests welcomed.