Hi Guys,
I used this approach starting with a segment of a sphere then circular array it,
worked quiet well, you could even do every second one with different panelling pitch.
Hope this helps.






Cheers

Definitely Danny's method is the way to go - that keeps things way more simplified for the booleans.

- Michael

Mr. Gibson - the 3DM file should contain everything necessary to recreate the problem. Note that I am using the beta V1, if that would make any difference.

Brian - those are really snazzy looking, but my needs are for a true 3D model for printing. Someday I hope to combine my modest designs with some really attractive shading/bumpmapping.

Danny - thanks, I'll give that a try as well.

Hi Yenmonger,

> Mr. Gibson - the 3DM file should contain everything necessary
> to recreate the problem. Note that I am using the beta V1, if
> that would make any difference.

Sorry - I had thought you were talking about another one of those vertical "longitude" pieces.

But I guess you are talking about the equator line one instead?

Yeah - that one is just barely grazing the vertical segments, it is difficult for the booleans to process intersections where surfaces kind of barely skim past each other.

If you scale that equator band either in or out by a slight amount, or use a larger sized square to sweep that particular one, it should create a slightly deeper or shallower groove which will more clearly push through the vertical surfaces instead of barely skimming along them. That kind of "clear push through" should allow the booleans to complete.

I did a quick test just now, and scaling that middle band from the origin by a scale factor of 1.01 seems to do the trick.

- Michael

I reported this kind of problem some time ago.


>>>Definitely Danny's method is the way to go

Well, that depends,.. if the user is happy with the segments then yes,.. but as when I reported the problem, I needed a single solid when finished, and trying to boolean union those segments is not always possible.

Hi Steve, you should always be able to get the segments into a solid - if boolean union gives you a problem you should be able to use Edit/Separate to break parts into their surfaces, delete any overlaps, and then use Edit/Join to glue the surfaces that have all touching edges into a solid.

Of course the segments need to be created precisely so that the pieces align well when you replicate them.

- Michael

Hi Steve,

> I needed a single solid when finished, and trying to boolean union those segments is not always possible.

Yes, that was a problem at first but then found that I could only boolean union 1 segment with the next then
when that was done I union that with the next segment and so on until I got a single solid piece. It wouldn't union in one go
if I picked all pieces, it gave MoI a brain strain ;)

Cheers

Hi Micheal,

>>if boolean union gives you a problem you should be able to use Edit/Separate to break parts into their surfaces

For a simple object as being put forward, then yes, but as at the time of my first report on this, the main problem came from the overlapping swept solids, I posted a very simple example to show you, and your reply was:-

>>The problem is with the surface/surface intersection part of the boolean,

so the first problem can be to actually get a segment with correct surface boolean, of course it can depend on the complexity.

Also:-

Surface booleans on a sphere may not be symmetrical, so splitting is not always an option.

Not all surface booleans are actually from a sphere.


- Steve

Hi Danny,

>>Yes, that was a problem at first but then found that I could only boolean union 1 segment with the next

I have looked at very many ways, but do find it "hit or miss",.. (sometimes it will/ sometimes it wont)


- Steve

Hi Steve,

> For a simple object as being put forward, then yes,

I was referring to this:

Any time you have a symmetrical segments like this, it should be possible to form them into a solid because you don't need to use boolean union to do this, you can have the segments be surfaces that have open edges and then use Join to form a solid.

That will be quite a lot more robust than boolean union because it will not attempt to find any surface/surface intersections between the pieces and will only attempt to join unattached edges together.

That should generally work to solidify any kind of symmetrical segments like this.


> but as at the time of my first report on this, the main problem came
> from the overlapping swept solids, I posted a very simple example to
> show you, and your reply was:-

Yes, correct - that was a situation with 2 surfaces crossing over each other and touching at a kind of crown point at the top.

That's a totally different situation than gluing segments like this into a solid.


> Not all surface booleans are actually from a sphere.

Certainly that's true - just to clarify, my comment was meant to be applied to the topic of this thread which is about booleaning things from a sphere.

If something does not have a kind of radial symmetry to it, then I would not recommend this method.

If it does have a radial symmetry, then I would recommend it, it cuts down on the lot of kind of crossing pieces that tend to be problematic, the smaller number of those the more likely that things will go smoothly.

I would not really worry about the final segment joining which you seemed to say was a potential problem - it you have any problem with boolean union there I would definitely think that Join can be used instead to solve that part.

- Michael

Hi Steve,

> I have looked at very many ways, but do find it "hit or miss",..
> (sometimes it will/ sometimes it wont)

If you have the situation where boolean union is not working and you have pieces that are touching each other edge-to-edge, then that is the situation where you can switch to Edit/Separate, discard the common pieces, and then use Edit/Join to glue together the pieces into a solid.

That method should not have any hit-or-miss about it. But the edges have to be matched up with each other for that way to work.

- Michael