Hello all. I'm playing with the MoI demo and just sort of trying to figure out the tools (coming from a LightWave / LWCad background). Can someone suggest a good getting started video tutorial? I see the list of them but it's kind of convoluted.

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.

http://screencast.com/t/ZWYyOWY0OT

Thanks. :)

Well in MoI V2 there is an "Edit frame" that will allow you to scale the top down a bit:



Or if you wanted to actually change the topology, you could creatre a cutting object and do a boolean on the top area:



Probably a bunch of ways, depending on what you are looking to do????

Thanks, I don 't want to scale the whole thing, Like I said In LW I would just grab the top and move it down like so:
http://screencast.com/t/MjIzODYxZmYt

I guess I could cut the top off with a boolean, but it just seems like that's more complicated than it should be.

Another problem is that the disc slot is also too high so you can't really change that with a boolean.

Yeah I think you would just cut the top off with MoI there. MoI CAN do something similar to this, in certain circumstances. Like if that object was created with a curve that was extruded or lofted or something, and you kept the curve there, you could turn on the control points for the creating curve and drag those down and the model would update.

Or select that top face and extrude it down and boolean that away from the original peice. (The same thing you show there in lightwave, with one extra step)

Michael has said he would like to add that "Automatic boolean add/subtract extrusion" mechanism, like Sketchup uses, to MoI.

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

There are also some other "low level" editing that you can do by breaking your solid into individual surfaces and operating at a surface level rather than on the joined solid.

For surfaces you can turn on control points and move the surface control points around, and also you can select trim curves that are not joined to other pieces and delete them to recover the underlying surface in those areas, that can be useful sometimes to erase a hole if you wanted to make a new hole in a different spot.

There is a tutorial on some of these techniques here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=446.17
But they are kind of more advanced techniques.



Also if you want to make changes it's not unusual to just delete some piece of the model and build a new fresh surface in there and then proceed from there.

One thing that is a lot different with NURBS than polygons is that you can make some big pieces of a model really quite quickly - so often times the solution is to just build a new portion of the model to replace the old one, rather than focusing on vertex tweaking of what you currently have.


Please do post your model along with your question though, it helps a lot to focus on a specific model when giving advice.


- Michael