Hi Renato - do you have a .3dm file for those curves that you wanted to Loft? If you could post those it would help me to show you some different ways of using them.

Basically when you loft between curves, if the curves are made up of the same number of segments (you can see the segments by doing Edit/Separate) then those will all line up with one another in a segment-to-segment basis.

But if you have a different number of segments and you want to loft them, then MoI will have to kind of merge together both sets of segments, that is what is causing that kind of slight twising there.

MoI is not really able to take different numbers of segments and intelligently match them, like in that case you probably want 2 segments of the top piece to merge with just one segment of the bottom piece.

But you can get that kind of specific matching if you use Edit/Separate to break those curves up into pieces, then perform the Loft just on the pieces that you know you want to align.

So for instance in the case you have there, I would recommend using Edit/Separate to break things all apart, then join together 2 pieces for the top part, and then Loft that to just the one part on the bottom. If you apply Loft like this in stages you can have much finer control over the segment matching and avoid that kind of automatic "all segments combine together" type problem.

If you can post your file .3dm, it would help me to illustrate what I have described above to make it clearer.

- Michael

Hi Michael,

Actually I wrote in the begining of the Post that I couldn´t upload a .3dm file because I´m using the Alternate Trial Version. But no problem, I can understand what is like answer all the discussions, sometimes you end up missing something... hehehe...

Now I can understand better what are the "conditions" to use Loft correctly. Thank You.

Actually I have some other doubts. Sometimes when I use JOIN it doesn´t JOIN everything in one, wasn´t it to join all the lines in one piece?

And I still have some problems with Boolean, like you explained about Loft, what are the conditions to Boolean work correctly? The only one that usually works like I want is the Boolean Diff. Problably I´m doing something wrong with the others Booleans, because sometimes it works sometimes not. But as I don´t know much about 3D modeling I don´t have the parameter to understand well by trial and error what I´m doing wrong or what I need to do.

I´m having some problems with Network too. I read the command reference but I stil don´t know what I´m doing wrong. I´m trying simple things but I don´t understand what is needed to work correctly. Sorry for so many basic questions.

Hi Renato,

> Actually I wrote in the begining of the Post that I couldn´t
> upload a .3dm file because I´m using the Alternate Trial Version.

Oops, sorry! I was just reading through your message too rapidly and ended up focusing on the pictures!


> Actually I have some other doubts. Sometimes when I use JOIN it
> doesn´t JOIN everything in one, wasn´t it to join all the lines in
> one piece?

Again it is difficult to give you a really proper answer without seeing the particular situation you're talking about (which is hard to do without a model to examine).

There are a few different reasons why Join can fail - if you have pieces that are too far apart (for surfaces edges more than 0.005 units apart) that will prevent them from joining together.

Also you can only join curves that touch end to end. For example if you have 2 lines that touch each other in a "T" type shape, where one is on the midpoint of the other, you can't join those together - Join for curves works by joining segments that touch end to end only.

Similarly you can't join a closed curve to any other curve.


> And I still have some problems with Boolean, like you explained
> about Loft, what are the conditions to Boolean work correctly?

Do you mean for booleans between 2 solids, or between 2 curves, or between a solid and curve?

Generally for a boolean to work, the pieces involved need to intersect one another, and divide the intersected pieces into 2 full halves. For example if you draw a sphere and draw a line from the top view that is inside the sphere, then that line does not fully divide the sphere into 2 regions and a boolean in that case will fail. However, if you make your line long enough so that it clearly separates the sphere into 2 halves, then you can do a boolean with it to cut the sphere.

Similarly if you have 2 solids, they should be intersecting one another and not just nearby each other or only touching each other at a point.


> I´m having some problems with Network too.

From the look of your curves, you have one closed curve along the bottom there - that is kind of a common problem.

For Network to function, it needs the curves to be able to be separated out into a kind of 2D flat map, similar to longitude and latitude lines on a map.

If the curve you have there on the bottom is just one single closed curve, it cannot be arranged like that.

Instead you need to pick an area for a "pole". In this case it could be either at the very top - for that arrangement you could keep the bottom curve all one closed curve, but then use edit Trim on the other 2 to divide those into 4 different shorter curves. With those 4 curves meeting at the top, that is then a latitude/longitude arrangement with that top point being the "north pole" of the map, and the closed curve being like the equator line. That will then work.

The other option is to split the closed curve up into 2 pieces by one of those other shorter curves. Then that will form a kind of "north and south pole" on either side where those curves touch each other in a point, and the one that you did not split with will become like the equator line.

Right now you have something that looks like a pole at the top, but it is not because those are not the ends of the curves - the curve keeps on going over the "north pole" - that makes it not a pole, only when the curves actually end at a spot will it be a pole point.

Does that make sense? Let me know if you need some more information on this one, I can create some illustrations for you if needed.

- Michael

Ahhh, the old trim trick for the network to work. When ever you can create a visual of the pole explanation, this may clear up several things for me also. I've been struggling on this too!

Thanks,
Burr

Hi Burr, here is a more illustrated example.

In the situation that Renato described, he had 3 curves, one closed one at the bottom and then 2 open ones. here they are shown separately for clarification:



All together these 3 look like this:




In order for Network to work properly, it needs to be able to detect a 2D grid layout to the curves. The 2D that I am referring to here really is the exact same kind of thing as the latitude (horizontal) and longitude (vertical) lines on a flat map which correspond to curved lines on a globe of the world.

The arrangement as currently shown is not possible to "unwrap" to a flat plane like a map. For example if you try to take the lower closed curve as a line around the equator, then that would mean that the other curves should be longitude lines that go up and have a common end at the "north pole" of the globe. But they don't end there, they keep on going past that area and end on the equator again.

In a 2D map of the world there is no such thing as a line of longitude that touches the equator twice, each line of longitude can only touch the equator once on a flat map of the world.

So the current arrangement is not suitable for unwrapping, it means it is also not suitable for Network.

To get a suitable arrangement, these curves must be diced apart. There are a couple of different ways to do it.

One way is to leave that bottom "equator" closed curve alone, and then cut the other 2 curves with each other (to do this, select them both, then run Edit/Trim, push "Done" or right-click at the select cutting objects prompt since you want them to cut each other, and then push "Done" or right-click again to keep all the pieces since you don't want to throw away any in this case).

This makes them into 4 pieces and now they are like pieces of longitude lines since they will end at the "north pole", here I have shown this arrangement slightly separated for clarity and with a red dot at the new "pole":



There are other ways you can do it too - you can instead leave those 2 upper curves alone and instead slice up that lower closed curve into 2 pieces, like this:



That creates 2 pole areas, it is like a globe lying on its side now. It doesn't matter which way the globe is oriented, as long as all the curves involved in the network can be organized into a 2D latitude/longitude set then they can be used for Network.

Hope this help explain the arrangement better!

- Michael

Here is another examination :

Kind Regards!!