Hi Phil, well those pieces have a pretty big and unevenly shaped gap between them... It's not particularly obvious to me how you'd want the connection to be shaped (EDIT: at first it wasn't but later when I saw how things were aligned from the top I think I understand).

Blend is not going to be feasible there because Blend is focused on making a smooth connection between 2 open edges. In your case here that means the blend wants to swoop off in this direction, so it will be smooth to those flat sides:



But the other edge you're blend with is not really in that direction, it's above it, that means the blend will be forced to try and do a sudden swoopy bank turn in a small area of space. That's going to produce a bad result.

It looks like these shapes are aligned from the top view, so my guess is that you'd want a planar surface along one side. You can use Loft to connect some of the pieces together but you would not want to do just one single loft between 2 complex boundaries that are made up of differing numbers of sub segments and sharp corners in it, to loft something like that you need to do it in strategic pieces, one loft for each side basically instead of trying to do it all at once.

In your case here I'd think you'd want to start with one Loft between these 2 edges:






Then I'd probably delete these 3 side wall pieces because you'll be constructing a larger plane in their place, that sticks downwards:




To fill in the back part you can loft between the 2 edges or also select this top edge and extrude it downwards:




Then for the side walls it looks like those are supposed to be one big plane, so you'd select these edges here and run Construct > Planar to build a planar surface there:




But unfortunately all your pieces in this case are not quite tightly on the same plane enough for Planar to work with them, so to fix that up while all those edges are selected run Edit > Join to glue them into a new closed curve object, select that curve object and go to the Top view and squish it down using "flat" snap (for an example of flat snap see here: http://moi3d.com/forum/index.php?webtag=MOI&msg=3378.4) and then run Construct > Planar on that flattened curve and hope that the pieces that were off were not too far off enough to be joined in to the planar piece.


Probably a better overall strategy for doing this would have been instead to build the whole upper piece as a sort of wedge-like solid with a side profile like this:




If you constructed that piece as a solid from the start, basically starting with that side profile and extruding it to get the base shape of it, that would make sure all the pieces were lined up. Then you use Construct > Boolean > Union to combine the base solid and the second solid piece together and it will form the edges where they intersect for you. Right now it looks like you're kind of trying to build it one little sub surface at a time rather than working with large solid chunks and using booleans to combine those solids chunks together - things usually go faster and easier when you work with solids and booleans as much as possible and only go down to the individual surface construction level for more difficult situations.

It also might be better to wait to form the hollowed out thickness part of the shape until after you'd got the sort of big protruding things combined first...

Or even without doing booleans and working piece-by-piece you would want this cut here to come from a vertical cutting plane that was the same plane used for the sides of the upper piece:



So you'd kind of want there to be some larger extended pieces like one big extended vertical plane that was common to both the top part and the cutout of the bottom part.


Hope this was what you were trying to do!

- Michae

I did a blend of the two back edges, and the two front edges.
Then did a network of the two sides using a short line segment in the two rear corners, and a tiny trim in the rear corners.
There are a lot of side segments to collect into joined curves.

- Brian

Hi Michael,

Thanks again for the in-depth explanations. It shows that I still have a way to go in terms of changing my mindset - which is fine as I'm not especially fond of the old one ;-)

More seriously, the bit about the "flat" snap is really interesting. I did try to use Planar in my numerous attempts but was stomped by the lack of alignment. This is really useful!

I am also starting to understand that I need to work more with large pieces at first and almost sculpt them down through Boolean operations as opposed to focusing too much on the detail first and trying to assemble things later.

It's quite late but I will continue work on this model tomorrow.

Cheers

Phil

@Brian - Thanks a lot for having taken the time to show me your approach. I'll definitely try it tomorrow (maybe combining it with Michael's explanations).
All the best
Phil

Hi Phil,

> I am also starting to understand that I need to work more with large pieces at first and almost
> sculpt them down through Boolean operations as opposed to focusing too much on the detail
> first and trying to assemble things later.

Yup, I think that's right.

There may be special cases where that's different but in general when you work more in that way with large pieces first, you will just tend to have more pieces meet up properly. Also many times it's just a lot easier and quicker to build an extended piece and then have some cuts on that to arrive at the final edges rather than trying to draw in all the final edges directly and then try to build everything directly to those. This process of relying on cuts rather than trying to directly surface each little individual patch can take a while to get used to.

It will get easier the more you do it! :)

- Michael

Hi Michael,

Thanks again for your help. This is the last time I bother you with my super basic beginner's questions for, hum... at least a week. Promised.

1. Naked Edges
Your method worked beautifully, but I'm struggling with making this a solid. I've found the very useful SelectNakedEdgesV2 script on the forum and it shows that new naked edges appeared in the side hole. It also shows a naked edge either on the new planar surface we've just created, or on the curved surface of the main body - I'm not sure which.

I've tried reconstructing some of the surfaces, but it's a vicious circle as it seems to be creating more holes... I've also tried to flat snap the uncooperative edges, but without success.



2. Fragmented Edges
The more I try to fix things, the more fragmented edges I get. Is there a way to easily recombine them again (Boolean Union doesn't seem to do it and Join creates a new curve but doesn't defragment the edges)?

3. Fillet
I thought that I would be able to fillet the hole situated on the side of the case, but I don't seem to be able to do so. Is it because the hole "crosses" several surfaces? If so, is there a way to do it?

Also what would be the best tactic to fillet the intersection between the case and the adaptor (highlighted in green in the picture below)?



Sorry for asking so many questions. I'm getting there, thanks to you and this great forum and the flood of queries will hopefully soon be reduced to a mere trickle...

Cheers

Phil

Hi Phil, I'll take a closer look at your model later on tonight, in at least one of those naked edge areas there is a little teeny tiny edge fragment where what looks like 2 edges is actually 3 open edges with one being totally squished down almost to a point. That will need some repair or untrim/retrim of those spots in order to get a clean join.

Also for filleting it makes things a lot more difficult for filleting if edges are fragmented into lots of little tiny segments rather than being long pieces. There is a Merge command that you can use to merge together consecutive edges that are smooth to one another into a single edge, that will probably help in some areas:
http://moi3d.com/2.0/docs/moi_command_reference10.htm#merge

But also ideally you'd want to avoid segmentation earlier on as well, like try to use curves that are made up of just one segment for smooth areas rather than made up of tons of little fragmented sub segments.

I will see tonight if I can help tune up your model.

- Michael

Hi Phil, also in some areas you've got some little tiny slivery surface fragments, possibly some remnant of some pieces being misaligned a little bit when cut with one another.

Here I've hidden all curves so only the solid and its edge are being displayed - it's subtle but notice that this area here looks a bit dark:



The edges are slightly dark there because there are 2 edges stacked up on top of each other there, there's a little squashed thin extra surface sandwiched in there, if I delete the big 2 adjacent surfaces there is this little weird piece left:



These kinds of little tiny squashed surface fragments will really mess up edge-based filleting. There is another kind of filleting which is surface-to-surface filleting, which is when you select 2 individual surfaces and run the Fillet command rather than selecting edges to fillet. That can sometimes be helpful for getting fillet surfaces to work with in areas where edges are messed up.

- Michael

Another thing that makes for difficulty with filleting is when 2 surfaces are fairly close to being smooth to each other but actually meet at something like a 5 degree angle. When surfaces meet smoothly then it also means that fillets traveling along that area will also meet up smoothly. When 2 surfaces meet at a sharp angle it means the fillet surfaces do not themselves naturally meet up end to end and instead need a corner juncture patch to be made. But when they are pretty close to being smooth the juncture piece may be some little slivery piece itself which things have difficulty processing.

Here's one such area along where you want to fillet that looks like it is not quite smooth but at a very shallow angle:




It would be a lot more "fillet friendly" if that was a whole smooth edge there, probably with those pieces being one single surface rather than 2 separate faces.

- Michael

Hi Phil, I've done some reconstruction work on your object and attached an updated solid version of it here. Basically I used some of the techniques described in the object repair tutorial (http://moi3d.com/forum/index.php?webtag=MOI&msg=446.17) to untrim surfaces and retrim where necessary to backtrack and get your object as a full piece like this:



Then I got the side planes of the upper piece arranged like this:



Then I used those planes both to cut out the hole in the top for where to connect and also the same planes were then also trimmed to use as the connecting side walls as well, that way with a common surface used the pieces are better aligned and can be joined without having any slight misalignments causing problems. I also untrimmed the side hole and recut that as well.

I think this has eliminated the little slivery surface fragments and also consolidated a lot of the fragmented edges so filleting will have a better shot on this one. I just tried a fillet for the area you wanted, and it seems that for smallish values like 0.5 or 1.0 it is working there, if you need larger than that, then some of the "slightly creased" surface meetings are probably getting in the way of those working very well, let me know if you still need help getting the fillet part finished. Here's what a fillet of 0.5 looks like:





Hope this helps!

- Michael

Hi Michael,

Thank you so much for your help and patience. This looks great.

I also appreciate the link to the repair tutorial which I had not found during my searches (doh!). I'm at work at the moment but will look at everything in greater detail tonight.

As promised I will stop pestering you for at least a few days ;-)

All the best

Phil