CATIA V5 Unfold feature

Leibolmai

New Member
Hey all,

I'm mostly skilled in V5, and we occasionally use the unfold feature in one of the shape licenses for various template constructions. It occurred to me that it could be a very useful tool for unfolding pesky NURBS files (catpart surfaces, iges, stp etc) which so far Pepakura doesnt handle well even post translation to a polygon model.

I'd expect that there aren't many CATIA users for home/hobby use, but has anybody else tried this feature to make paper models out of? I did a test rectangle today, had to tell it which edges to tear but seems to have come out good.

Cheers,

Leibolmai
 

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Z

Zathros

You got me thinking when you said NURBS. I stay away from Pepakura because many of the models have an ungainliness to them which seems difficult to transcend. This was some stuff I was playing with in Rhino. It is completely done in Rhino. It is about 10 minutes worth of doodling.
The Box with the Roof with two holes unfolded. The Dome over the cylinder, split and petaled, I prefer conical sections myself. The word Zealot projected onto the cylinder, then unfolded. The word unfolds with the command if you select them together. Just playing around. :)
 

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Hello, I happen to work for DS mostly on V6 development and was wondering if anybody tried using CATIA for paper craft. Unfortunately while I know V5 and V6 from the inside I am not a skilled user. Ironic isn't it.
 

Leibolmai

New Member
I played with Rhino yesterday too bringing one of my work models over. Complex skin, and Rhino's unrollsrf command kept giving me an error on certain pieces about no double back or something like that. I have absolutely no Rhino skills, we have it over here since its helpful in recontructing 3D scanned data from point cloud to polygon or NURBS. Do you know of any good tutorials?

I went back to catia and had no issues. I found it pretty much unfolds anthing as long as you cut it into quarters. So if you have a really complex shape, say a fuselage, if you cut it in half vertically down the buttline it may or may not unfold. But if you cut it in half both vertically and hortizontally down the middle you can unfold the quarters.

I can't show pictures, but so far I've got two of our aircraft unfolded. I've given some thought on how best to reassemble, I may copy the unfolds and paste them onto the same plane, then take image shots. The issue is the zoom level is going to effect scale, so i may have to mark out some rectangle around them to scale too later.

Obviously, CATIA has too large of a pricetag for normal users, so I don't think its going to make a huge splash in the paper modeller market :)

Cheers,

Leibolmai
 
Z

Zathros

Well, Rhino has incredible unfolding abilities, but you need to use the "Squish" command and "Squash" command to try and unfold compound curves. Just so you know, Catia may be unfolding them, but that does not mean that those unfolds will fold back into that shape. I attached a model that I have worked on, I don't have any plans to release it. but it is something that many have tried to model with not so good results. I was pleased with the final model. It is very different going from something that is going to be machined or formed into shape opposed to making something with paper's limitations. As far as tutorials. I tried doing that, but I found that people did not stick with it. Rhino isn't something I have seen anyone master but then again, I haven;t seen anyone master any CAD program. You just work with it.


Rhino is really good if you learn how to form surfaces and make the shapes you need for yourself, rather than take a shape that someone else makes, as far as paper models go. The attached renders unfold effortlessly, though I can't say they went together that way! .
:)

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Leibolmai

New Member
Nice stuff. I may have to look into Rhino further. Since I'm experiementing with existing skins I can't show pictures of WIP's, but if I get a paper body made I can share that. I have the fusleage printed out with no tabs made for test purposes. I'll let you know how it goes. You are correct on the unfolding not necessaryily meaning it will go back together, there were a few times where CATIA overlapped edges during the unfold so impossible to cut it out (basically two pieces occupying the same 2d space)

Cheers,
Leib
 
Z

Zathros

If you use the Squish feature, and allow it to separate seams, you can get a nice part. This is a Cessna fuselage I was working on. I am working on a different technique of building these things. It is an example of what Squish, and playing with the control points can do. his goes together rather nicely. :)

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Leibolmai

New Member
Excellent. See those triangle cuts into material that would help in the folding, that's what I have found CATIA is missing! It seems to stretch across those sections during the flattening. I'm trying to figure out a work around, but this is new ground on what we've use the unfold feature for and I haven't found much in the way of tutorials.

I'll post pics of paper model when I can but been very busy. Will give you all a sense of what I am attempting.
Cheers,
Leib
 
Z

Zathros

Sounds good. Let me know when you've posted something, in case I miss it. :)
 
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