you are welcome)

Neat!

Hi mir4ea, that's a great overview!

One other command that is generally related is "ShrinkTrimmedSrf":
http://moi3d.com/2.0/docs/moi_command_reference10.htm#shrinktrimmedsrf

It shrinks down underlying surfaces, until they are just big enough to hold the trim curves. Sometimes that is useful if you have trimmed away a large area of a large detailed surface for example and only have a small fragment left, by default the whole original surface will still be underneath everything but when you do ShrinkTrimmedSrf it will shrink it down and only keep the area around the current active area. Then you will get a different result when you do an "untrim" afterwards.


This whole overall mechanism of having "underlying surfaces" and trim curves is what makes NURBS modeling very different from polygon modeling, and it's also why NURBS modeling works well with boolean operations, because when you do repeated booleans onto a NURBS object, the original surfaces stay all the same and only new trim curves get created or modified, it helps keep the original surface structure to stay simple. With polygon modeling when you try to do booleans it fractures things into more and more polygons which builds up complexity on each cut.


- Michael

Thanx Michael, now I can understand what this command do) And yes it could be useful especially when the underlying surfaces is big to reduce its size. Or may be there is the other point to use it?

And one new definition - underlying surface (surface in its original state).
Another fundamental definition - trim curve (http://moi3d.com/wiki/FAQ)

In another words ShrinkTrimmedSrf command reduce size of initial state of surface, make it fit to your trim.


Michael I think this definition have to be on the first place in tutorial list) Because it's how nurbs works on low level.
Now knowing this, I am sure I'm more confident in nurbs modeling.
It's peaty a bit that I know it accidentally after half of year of using MOI :)

Hi mir4ea,

> Thanx Michael, now I can understand what this command do) And yes it could be useful especially
> when the underlying surfaces is big to reduce its size. Or may be there is the other point to use it?

Well it can help reduce file size if you have only small remaining pieces cut out from much larger and complex original surfaces.

Sometimes it can also help avoid problems in complex operations like offsetting since it has a kind of simplifying effect. If you have surfaces that are self intersecting or bunched together awkwardly but those bad areas are outside of the active trimmed area then this command can get rid of those bad areas of the surface.

So sometimes if you're having a problem with complex operations it can be worth a try to run it to see if the shrunken down surfaces behave better with that particular operation. But after you do it, it's not so easy to restore the full original surface later on by untrimming though, so you it's not something that you would just do all the time automatically.

- Michael

Hi mir4ea,

> Michael I think this definition have to be on the first place in tutorial list)
> Because it's how nurbs works on low level.
> Now knowing this, I am sure I'm more confident in nurbs modeling.
> It's peaty a bit that I know it accidentally after half of year of using MOI :)

I've tried to explain it in the FAQ with some illustrations there too... But it's such a different structure than how polygon mesh geometry works that I think it can just take some time and experience with working with surfaces for a while first before it really sinks in.

It's also the reason why you can't just grab any edge that you see and pull it around like you can do in a polygon modeling program, because often times the edges in a NURBS model are set up more like markers that mark some areas of the surface as active and others as holes. The actual surface shape comes from the "underlying surface" and so to modify the shape means modifying that surface's control points and not the "markers".

In a polygon mesh modeler every edge that you see is not just a marker but the edge of a little polygon surface, there is not any concept in a polygon modeler of there being edges that are just "trim markers" instead of being a direct defining part of the surface geometry.

- Michael

in English this time ;)

Good illustration)

There are so many useful scripts around! And all have to be met somewhere, in the forum discussions, and installed one by one. I think that it is necessary to put them to a scroll, with corresponding icons, (which will appear by clicking a single 'scripts' button somewhere in the ui) and implement all of them in the v.4 as standard tools. This will help very much. I know, there is already such a solution as an add-on but it would be better to have it as a native feature in the app.

Hi Dimitri - eventually I do want to make a script browser built into MoI. There will be quite a bit of work involved in doing that though so I'm not sure when it will happen, definitely not for v4. Just making a huge list of all existing scripts isn't very workable because many of them are very specialized to help with one person's particular problem.

- Michael

'Just making a huge list of all existing scripts isn't very workable because many of them are very specialized to help with one person's particular problem.'

I do understand it Michael but some add-ons are really very often needed and used, so it would be very helpful to have them as native tools in a coming version. Having such tools in a browser which opens by a 'further tools' button on the ui would be of immense help indeed. It will make things very easy to handle. Such a thing would not overcrowd the ui and, in the same time, would give easy access to a variety of important secondary tools.