Hi NightCabbage,

> It's funny how I seem to have a different perspective of
> how things could be done in a 3d environment...

Actually the way that you were talking about doing it does fit into a polygon modeling type of system which is a different kind of 3d environment than MoI's method.

There are actually a lot of different possible methods out there for building 3D models.

- Michael

Hey Cabbage,
Also remember that it makes it alot easier if you have a question to post a file along with it. It helps to eliminate some confusion about a particular model or modeling question.

Good luck.

Danny,

Oh Yeah. thanks for reminding me.

I'm back to folding plans now. ;)

Ok, so I've been palying with Moi a bit today, and aside from having great fun, I'm actually getting it to make the stuff I want :)

But I still regularly come up with the problem of wanting to just change a particular line/curve of an object...

And I'm wondering why it isn't possible to do this (without separating the object)?

Example 1:



The above is one solid object.

However, during the making of the object, a circle (blue colour) was cut into the surface (yellow colour).
(I coloured the circle blue myself, by the way lol - don't have V2 just yet hehe)

Is there any reason why I can't just delete that blue circle, and have the yellow surface without that circular hole?

Example 2:



Once again, the above is one solid object.

But what if I wanted to change the shape of the exhaust?
Or perhaps I want to move the whole exhaust to a different place on that flat surface?

For my usage, this is the number one "most wanted feature" :)

Begin able to edit existing shapes by their internal components (lines and surfaces - though of course the surfaces are created automatically by the lines, but the surfaces should control the surrounding lines)

What do you think?

-EDIT-

Oh and I've read the FAQ but still think that this feature would be worth implementing / figuring out.

Hi NightCabbage,

> Is there any reason why I can't just delete that blue
> circle, and have the yellow surface without that circular
> hole?

Actually you can do that - if that blue circle is a circular disk type surface, select it and delete it first, which will leave an empty hole. Then you can select the remaining edge in the yellow surface to "untrim" it and recover the underlying surface in that spot.

Here is one post that describes untrimming in more detail:
http://moi3d.com/forum/index.php?webtag=MOI&msg=444.4

Also here is a more complex mini tutorial that talks about using untrimming and re-trimming to repair an object that had a boolean done to it in an incorrect location:
http://www.moi3d.com/forum/index.php?webtag=MOI&msg=446.17


> Once again, the above is one solid object.
>
> But what if I wanted to change the shape of the exhaust?

You normally would just delete those faces that make up the exhaust and then construct a new one there instead.


> Or perhaps I want to move the whole exhaust to a different
> place on that flat surface?

You can basically detach the exhaust surfaces from the rest of the object by selecting those faces that make it up, and then using Edit/Separate. That makes those faces into an independent object which you can move somewhere else.

There's an object repair tutorial that goes into much more detail about this which is available here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=446.17


> Begin able to edit existing shapes by their internal
> components (lines and surfaces - though of course the
> surfaces are created automatically by the lines, but the
> surfaces should control the surrounding lines)

In the future I would like to make it possible to edit the model by moving edges around, but the way NURBS are structured it is not really an easy task to make that happen. It involves things like merging trimming boundaries, extending surfaces, stuff like that. That's because with a NURBS solid the edges that you see are not necessarily the edges of the "underlying surfaces", they may be trim curves which are just on the surface but not necessarily aligned with the surface's natural edge, which is a much different structure than how polygon meshes work.

There are some other NURBS modeling systems out there that have refined that kind of editing to a greater degree, one example is SpaceClaim, if that kind of editing is a big concern for you, you might want to check it out.

- Michael

"There are some other NURBS modeling systems out there that have refined that kind of editing to a greater degree, one example is SpaceClaim, if that kind of editing is a big concern for you, you might want to check it out."

Ah, but I really like your work, Michael, so I think I'll stick with MoI :)

I do think that the ability of being able to move things around like that would be a great asset to the program, as many professionals out there are used to this kind of feature in poly modellers, and having it would be a great draw-card to your program.

"un-trimming"

Oh, that was easy - I thought I'd already tried pressing delete on the edge at least a dozen times?? lol
It's pretty intuitive, so that's good (no idea why it didn't work before!)

-EDIT-

"In future versions I should be able to add more options for doing this kind of thing more automatically, for instance it could eventually be possible to enable dragging the hole around without erasing it first, or using history to change the size of the object being booleaned. But for V1 these won't be ready so the "erase hole" technique is what will work for right now."

Hehe, this gives me hope that you have it planned! :)

Hi NightCabbage,

> I do think that the ability of being able to move things
> around like that would be a great asset to the program,
> as many professionals out there are used to this kind of
> feature in poly modellers, and having it would be a great
> draw-card to your program.

Yup, I definitely agree!

The reason why it hasn't been added yet is not because I don't think it would be a good and useful feature, but just because it is not an easy thing to implement and will take some hard work to enable it.

- Michael

Hi NightCabbage,

> It's pretty intuitive, so that's good (no idea why it didn't work before!)

Well, if you select the edge while you still have that blue surface in place, it won't delete. Untrim only works on edges that are not connected to other things, so you have to delete the blue surface first before having an open hole there... Maybe that was what you ran into?

- Michael

Quite possibly :)

So general rule:

You can always delete surfaces, but you can only delete lines that don't have any dependant objects (like a surface).

Hi NightCabbage, yes that is correct.

Also to delete edges you need to select the entire loop that forms the trimming boundary. Like for example if you have a square hole with 4 edge making up the hole you have to select all 4 of those edges to delete, not just one of them.

- Michael