Hi phil, your best bet for some introductory videos are the ones that are part of the main documentation here:
http://moi3d.com/2.0/docs/tutorials.htm
Those are the first one listed in the tutorials section of the wiki, and they go kind of more slowly and with more discussion than many of the other videos, so they are more suited for a general intro.
The other ones can be helpful for solving a more targeted problem once you already have some familiarity with the tools.
> My first problem is that I very quickly slapped together this
> PS3 model, just playing around, no measuring or anything,
> and the top part is too high so I'd like to correct it of course
> with polygons you'd just grab it and move it down. It's a little
> more confusing here.
Could you please post the 3DM model file of your PS3 here as a file attachment? That would make it easier to show you stuff using your exact model to demonstrate.
But in general the structure of NURBS objects do not really lend themselves naturally to yanking around faces or edges as you would in a polygon modeler.
That's because the edges that you see in the model are not necessarily the edges of the "underlying surfaces" - in a NURBS model there is a thing called "trim curves", which mark different areas of a surface as being active or inactive (like a hole), but which are separate things from the actual surface.
There is some more discussion and illustration of how "trim curves" and an "underlying surface" works here:
http://moi3d.com/wiki/FAQ#Q:_Why_does_show_points_work_for_some_objects_but_not_others.3F
So that's a much different structure than polygons, in a polygon modeler the edges you see are always the natural boundaries of the surfaces involved, while in NURBS the actual surface control point structure can be a lot different than the trim curves that are on the surface marking active/inactive zones.
But this same NURBS structure that does not allow for yanking pieces of solids around so much is also the same reason why boolean operations work a lot better in NURBS than in polygons - when objects cut one another in NURBS the surfaces themselves do not have to get more complicated, only new trim curves are calculated on each of the surfaces. This helps keep things much more simple in structure, in polygons one of the problems with booleans is that surfaces become fragmented into a zillion little shattered bits that are harder to manage in many ways.
But if you post your model it would allow us to more easily give some feedback on how to get what you want, you would probably build a cutting piece and use a boolean. You can build the cutting piece by a surface extrusion if you want which will give you the same kind of result as moving the surface vertically.
In the future I do want to add some more kinds of "direct editing" tools that would handle altering solids in the way you originally wanted by just moving faces around. That's not available yet because it is a lot more complex to set that up with the whole "underlying surfaces" and "trim curves" type structure, surfaces and trim curves have to be extended and things like that, it's a lot more stuff involved than just moving vertices around like in a poly modeler.
- Michael