Hi friends,

i've got many problems to build a union with the boole function.
I'm modeling 3 parts of an fuel cell. Here is the link, where you can see what i mean.
http://www.kts-cable.com/uploads/pics/DSC06413.jpg (hope this works here)
For more pictures, take the search term "jenny 600s".

The problem is with the front surface of the indentation.
I attach the file at once. Here you can see very quickly what I mean.

How do I get the 3 parts to a joined surface? I would then smooth the edges slightly.

Cheers
Jörg

I see two sine waves, and Grun and Cyan items also, Stacked up there.
Deleted the sine waves, and hid everything but the 4 (not 3) blue surfaces, and used Boolean Union to get a Joined srf.

?

Hi Jörg, I'm a little confused about what you're asking about - you are mentioning 3 parts, but I only see 2 parts in the model you attached, this one here:



And this one here:



Are those the ones you're trying to boolean union together?

You can run into probems with 2 parts that are just barely skimming each other with only overlapping surface area and not actually pushing through each other. If you have 2 things that are just skimming over the same surface area like that, they will need to very accurately coincide in order to be unioned. Your 2 pieces look like they are slightly different in shape, one piece has segmentation here:



While the other does not:



You might try moving the pieces a little bit so that they are pushing through each other a little bit instead of barely skimming, or you could try building the pieces with the same structure so that they would be more exactly touching one another instead of one maybe dipping slightly in and out of the other's surface area, or possibly a better method might be to build the whole body as one larger piece and then instead slice a groove in it.

It's not totally clear to me whether those 2 parts are actually one solid piece in the actual object with just a groove in that separating area or whether it's 2 separate pieces. If it's a groove you may want to model it more like that with the whole thing as one big piece and then cut out grooves.

- Michael

Hi Jörg, or were you talking about that front Blue piece like Bemfarmer is talking about above? That seems to be a piece that's already been booleaned into place though is that correct?

I'm not entirely sure if I understand which pieces you are asking about...

- Michael

Or is your problem more that the bigger piece is not a solid?

There are some "naked edges" around the blue piece - that means that there are some gaps there were that piece did not touch closely enough to the other surrounding objects to get fully glued together.

It also looks like there are some little slivery surface fragments in some areas there too, so possibly that blue piece did not get constructed very cleanly or something like that, that piece may need to be rebuilt and rejoined in, in order to make a fully closed solid main piece there.

Is that the area that you were asking about - are the 3 pieces then the blue piece and then other 2 ones on either side of it?

I think that's maybe what you were meaning, sorry for my confusion - it's partially joined in some areas and not in others, so that makes it select still as one object even though there are some places where it is not sealed up.

One thing that can help to see where you've got problem areas is to set up a shortcut to select "naked" (unjoined) edges, as described here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4869.5

- Michael

Also one other tip - when you have 2 surfaces that share a common edge and you want to glue them together, it's usually best to use the Edit > Join command to do that rather than Boolean Union - Boolean union is focused more on combining 2 shapes together where they are actually intersecting one another and need to have some area removed from the combined result.

If you know that you only want to glue touching edges together and don't need things to be intersected and have material removed, the Join command will only do that kind of gluing and not try to do intersecting.

It may be possible that you've got some slivery pieces generated because of using booleans where they're trying to cut things with each other in this case.

- Michael

Thank you bemfarmer,

I mean all areas of the entire (front) object.
So the entire object.
The loft is not the problem, just as the main body.
But all three objects to merge into one and then get 1 object,
turns out to be difficult for me.

In the picture you can see what I mean.
The solution of the problem lay in the open edge.
After re build the curves, there were no more problems.
I do not understand how these open-edge form.

Hope you can understand my english :)

-----------------------------------------------
*edit

We're talking about the front part, which consists of 3 parts.
The goal is to merge the three parts to one part in order then to round the edges.

After connecting the parts now is a small hole between the red and the orange part.
But it is a closed surface. What I understand there is not or what I'm doing wrong.

The first picture shows the hole between the surfaces.
The second picture shows the staggered edge.

 

I always need some time to read the articles here and understand ...
and it is now 1 night clock. I must go to bed.

Good night and thank you for your help.
I look at us again tomorrow.

Hi Michael,

hmm when i use the "join" command to connect the two (or three) parts,
i can't use another tool to fillet the edges. I talk about 123D. I like the fillet-tool a lot.
It is very flexible. 123D needs a STEP file, and it must be a closed surface.


If my skills are better in Moi,
I change my software also no more, I promise;)

Hi Jörg, there are some irregularities in some areas of the model, like for example there's a little teeny tiny hook-like edge in this area here (from your first posted file):





These kinds of teeny tiny and also squiggly little edges are going to be problematic, basically those areas need to be rebuilt to be cleaner before you'll be able to get things joined up well between them.

I'll see if I can help you to make a tuned up version.

- Michael

Hi Jörg, I've attached a 3DM file for a version that is joined into a solid, I untrimmed and retrimmed various pieces to fix some of those structural problems that I showed above.

It should now import into 123D for you, and you'll probably have some better chance of getting the fillet done over there - you'll likely run into some problems filleting that area with MoI because I think the various pieces are meeting up at some slight shallow angles to one another rather than being smooth to each other.

I think some of the parts that look like arcs are connecting together not by the arcs endpoints but by some point inside of them, that makes for a very slight shallow angle between the pieces and MoI's fillet engine tends to have problems with such shallow angled pieces.

Here's an example of one of those shallow crease areas:






If you had those pieces meeting up more fully smoothly to one another instead of with just a slight few degrees crease between them it would have a much better chance at being filletable in MoI's fillet engine - it tends to be pretty sensitive to this particular kind of situation of things meeting each other almost smoothly but actually being a few degrees off from actually being tangent to one another.

Anyway I hope the attached solid 3DM version is helpful for you.

- Michael

Hi Michael,

thank you for you support -and all other too, a big THANK YOU!-
Your model looks great, very clean and it is ready to fillet the edges.

Can you explain how you solved the problem?
How do you get away the unnecessary cuts / edges
without having to re-engineer all need?
I can look at the file, but do not the way to solve the problem.

New cuts are set through trimming?

My approach is this: I Separate the parts from each other, then create the curves from the edge selections. I use for lofts or sweeps.
I'm not sure whether this is the right way.

To generate the curves from the edge, it seems to me to be the only way to create new interfaces between existing areas.

The edges of your model are continuous! How did the surfaces have created?

Greetings
Jörg

I need to watch more tutorials to understand how to model in Moi working properly in order to get a clean result.
Do you know a tutorial that such topics treated?

Hi Jörg,

> Can you explain how you solved the problem?

I used "untrim" to erase the trimming boundaries on those pieces and that then recovers the full original underlying surface, I then retrimmed them with your curves to make a better quality trimming boundary.

There's a short description of untrim here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=444.4

And there's a longer tutorial on these kinds of object repair techniques here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=446.17


> How do you get away the unnecessary cuts / edges
> without having to re-engineer all need?
> I can look at the file, but do not the way to solve the problem.

There were some areas where there were several cut up pieces that were actually parts of the same original surface. When 2 surfaces come from the same exact underlying surface you can use boolean union on them and it will be able to eliminate any in-between edges in that case, it can also heal (remove) edges between 2 co-planar planes in the same way.

So to clean those up I used Edit > Separate on your model to break it into individual surfaces, then picked 2 of those fragments at a time and then did boolean union on the 2 fragments to get a result without any interior edges.


> New cuts are set through trimming?

Yes, after an "untrim" to get rid of the badly formed boundaries then I used Trim after that to cut it to a cleaner new boundary. At one point I took one of your longer curves and flattened it down to 2D to use as part of the trimming boundary.


> My approach is this: I Separate the parts from each other, then create the curves from
> the edge selections. I use for lofts or sweeps.
> I'm not sure whether this is the right way.

This is how I formed the actual surfaces - however you need to have clean trim boundaries in order to use this technique - things like little tiny weird edge fragments like you had before will lead to problems.

Once I got all the edges set up cleanly I picked 2 edges at a time and did a Construct > Loft to build the surface between them, then those pieces were joined to the other ones.


> The edges of your model are continuous! How did the surfaces have created?

In some areas I used the Merge command to merge together a bunch of fragmented edge segments into longer edge pieces:
http://moi3d.com/2.0/docs/moi_command_reference10.htm#merge


But it's actually best to try and avoid needing to do these kinds of repairs in the first place, if possible you want to get the model constructed out of somewhat more simple and cleanly meeting pieces from the earliest stages.

- Michael

Hi Jörg,

> I need to watch more tutorials to understand how to model in Moi working properly
> in order to get a clean result.
> Do you know a tutorial that such topics treated?

I don't really have a whole lot of tutorials in general - the ones that are available are listed here:
http://moi3d.com/resources#Tutorials

One general tip is to try and build some pieces more as extended pieces initially that then get cut to their final outline, rather than going around and doing things in a "patch by patch" manner.

There are some tips for people from a poly modeling background here which may be helpful:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4865.2

- Michael

> So to clean those up I used Edit > Separate on your model to break it into individual surfaces, then picked 2 of those fragments at a time and then did boolean union on the 2 fragments to get a result without any interior edges.

Yes, this is a good way to rebuild objects. It works fine :)
Thanks for the description in your links.

The additional commands are great! At this point i didn't know the other commands, but the "rebuild" function for curves.
I now understand much more about how to create "clean" surfaces in Moi.
Your support helps me a lot!

Thank you!

Jörg