Hi eric - yup that's possible now - to do that create your block object so that it has its base point at the 0,0,0 origin point and is aligned to the world axis directions. Or you can also set up the cplane with the cplane origin and axis direction positioned at the particular base point and base orientation that you want for the part.

Then save that object to its own 3DM file.

Now when you want to bring that object as a piece into an existing model, go and right-click on the File > Import button instead of the regular left click. When you right-click on Import it will run the "ImportPart" command, which will bring in the contents of that file and also allow you to locate and and position them into the particular location that you want using the orientation picker. That will do not just a move of the object to the place you want but it can also rotate the object into place to align it to the plane surface that you are snapping on to. You can disable the rotation if you want by unchecking the "Align to objects" option when placing the object.

The placement works as a 2 step process - one click to put it into an initial position and then after it is placed there is a second stage where it is possible to rotae it around one of the axis tripod directions if you want, right-click when you're done adjusting the rotation - probably when snapping on to a plane you won't need to adjust the rotation so you'd just right-click to accept the default position. So anyway you'll do 2 clicks to do the placement - one left click to place it and then right-click to accept the default rotation.

The way the rotation works is that it will align the z axis of the base position with the surface normal direction, so that means that you want to put something like a window to be flat in the x/y plane in the library file.

Some more information here:
http://moi3d.com/2.0/docs/moi_command_reference1.htm#importpart

http://moi3d.com/2.0/docs/moi_command_reference11.htm#orientationpicker


- Michael