Lofting really complex sketches causes intersect warning

[Anonymous]

Hi,

I'm trying to create a small statue for 3D printing. The statue consists of multiple lofts, one of them giving me a hard time. And I'm not surprised.

The 2 sketches I'm trying to create a loft from are actually 2 simplified geographical maps: North Korea and South Korea (see attached DXF's). When selecting both profiles for the loft, the following error occurs:

Warning: The loft would intersect itself.
Try changing the inputs to avoid this. If you wish to build a self-intersecting shape, try building the shape using multiple lofts.

I can fully understand if this would be too complicated for the loft engine to process. However, it did work a few times and it created exactly the loft I wanted. It looked like a tree with many vertical lines.

Then I made some minor changes to the maps and now it just doesn't work anymore and it's driving me nuts.

What would be the approach to solve this? I assume railing won't help in this case, because it would take away the tree-like shape.

Any help appreciated!

Thanks,

Rudi

[mavigogun]

Can you attach the Fusion Archive directly to this thread?   Doing so will present how you expect the elements to interact.

[Anonymous]

Hi @mavigogun,

With "Archive" you mean the model? Model with 3 sketches (https://a360.co/2Ohnvpy)

Interestingly enough, while creating this example for the forum thread, I tried to loft with an additional sketch of a circle between the 2 map sketches. (Actually the advice in the error message). So it's a 3 sketch loft now (North Korea -> Circle-> South Korea), and it works!

So it must be that the 2 geo map sketches are just too complicate to loft between them. I still don't understand why it worked before, but should I care? (Well, the nerd inside me wants to figure it out).

Some background on the input SVG files:

I have the Korean maps in PNG. I clean them up first in Photoshop (get rid of islands and some other stuff).

The resulting PSD file is then opened in Illustrator where I create (Image Trace) the path, which I then export to SVG.

The SVG is imported in Fusion as a sketch. The resulting paths can be complex with many lines and anchors (I guess they are called edges and vertices/connection points in Fusion). 

Anyway, if you can have a quick look at the model and maybe come up with another reason that the map-map loft fails, that would be great, but since the result I need is already there with the 3-sketch loft, I can understand if you want to drop this post.

Thanks for responding and I'll drop the final result of the statue when it is finished. It is a present for an adopted Korean friend.

Bye,

Rudi

[mavigogun]

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@Anonymous wrote:

With "Archive" you mean the model? Model with 3 sketches (https://a360.co/2Ohnvpy)

Uuuh... yes- and no:  you're more likely to receive address by attaching the Fusion archive directly to your post- as shared above, would-be-helpers must Click Link > Load Page > Click Link > Enter Email > Open Mail Client > Open Mail > Click Link > Import File.

That said, I'll take a peek; likely the culprit is the number of segments.

[mavigogun]

I Lofted successfully using the transitional circle in the Patch workspace- that said, it doesn't read well.   Check it out:

[mavigogun]

An in-plane variant:

[Anonymous]

Thanks for the tip, I'll keep it in mind.

[Anonymous]

Mhhh, I like your loft starting from the circle even better.

The person I am making it for was adopted from South Korea, but her parents came from North Korea. Her name translates to "Beautiful heart". So my thought was: create a tree that starts growing from North Korea, passes South Korea and ends in the shape of a heart. The problem with my idea is that you don't see the actual shapes.

Now I'm thinking, using your idea: start with a circle and create 3 'branches' with NK as the lowest branch, SK as the middle branch and the heart-like shape at the top. More like a bonsai tree. I'll give it a go today.

Many thanks for the inspiration!

Bye,

Rudi  

[Anonymous]

Btw. Sorry for the confusion between Darius Klein and Rudi Klein. Darius is my son, we get our logins mixed up once in a while :-). It's always me: Rudi

[mavigogun]

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@Anonymous wrote:

Darius is my son, we get our logins mixed up once in a while :-). It's always me: Rudi

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Wow- a designing family! I'm jealous! 

That space left for us to make design decisions is where art is located; do me a solid and post your solution when it arrives- I'd like to see where the story goes.

[Anonymous]

@mavigogun

You could say "design family" or "bunch of nerds" (2 sons). It's all tech and ideas here.

My poor wife: she's on the empathy and support side of the spectrum 🙂

I'll definitely show you the result.

[Anonymous]

Hi @mavigogun,

Here are some intermediates. It is all one single body, built from many joined lofts. To keep a natural look, without using sculpting and because of the limitations of the lofting engine (or my PC), I decided to break it down in parts.

Every single loft goes from complex sketch to a circle or ellipse and vice versa. The circle makes the lofts simpler.

It also gives me control over the shape of the body: I can modify each sketch a bit or rotate/scale them.

I have built a stack of planes, 10-30mm of each other and on each plane I created a sketch, either a circle/ellipse or a slice of a trunk, derived from an actual section of a trunk PNG image (why design a trunk section, if nature does a better job). 

I still have a couple of things to do: repair the nasty hard line in the stem of the heart, apply the name into the tree as a cutout and add roots (which appears to be a challenge). And then print it in wood PLA , which will be again a nice challenge.

But let's face it: if it was easy, it wouldn't be that much fun...I guess.

I'll post the final thing when it is ready.

Bye,

Rudi

[chrisplyler]

Roots?

[mavigogun]

Sweet!   With this approach, not making the profiles co-planer sure seems like a good idea.    I suppose if you wanted to make the length ridges contiguous,  you could loft another body that closely associates with the first, ridges poking through, and just combine them in the STL export.

[Anonymous]

@mavigogun

@chrisplyler

Hi guys,

I've been busy with some other stuff, but...the tree statue has been printed! And it looks amazing!

I don't know if you are into 3D printing, but the tree is printed in a wood filament, birch actually.

I used a wide nozzle of .8 which I normally wouldn't use, because it creates a low 'resolution' print. In this case however, it really makes the print more natural looking. Even the small lumps makes it look better! 

It took 11 hours on the Anycubic i3 Mega, but it is worth it.

The picture below shows the actual printed object, a bit back in the thread you can see a pic of the model.

@mavigogun

You can see that I actually preferred your idea instead of mine. Breaking it up in 'branches' suits better with the concept I had in mind: a flow from North-Korea (birth country of my friends parents), South-Korea (birth country of my friend) and the heart (my friend, "beautiful heart" was the name that was given by the parents).

The inscription in the front is het official name: Hye Jung. So all the important symbols are in the tree.

Many kudo's for your help, it i much appreciated! 

@chrisplyler

I have tried roots, but decided against it at the end. Thanks for the input though.

The final model is available through the link, be my guest to download it if you like.

The model became so complex in the end, that any adjustment seems to blow up F360 :-).

I probably would do it a little different next time, but this was my first loft.

As @mavigogun mentioned, there are improvements possible in the method I used to make it even more natural looking.

Thanks again.

Rudi

The final model

[mavigogun]

Sweeeet!