Full Version: Boolean Fail

Hi Michael,

Just trying to create a single part from this geometry boolean union failed to merge - no problem in boolean union in RHINO. Any thoughts welcome.

Have tried MOIV3/V4 same problem.

thanks
Alex.

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Hi Alex,

After trimming with a rectangle, to yield one square tic-tac-toe grid, after MANY boolean unions, and one trim to get an extra side to the inner square,
(and 4 planars to close the 4 open ends,) a solid resulted.
There were some leftover small curved triangular surfaces to delete.

In another limited trial, mutual trim resulted in successful boolean.
The whole grid did not mutual trim, after a couple of minutes.

- Brian

Some other subsets boolean just fine...some do not.

It will be interesting to see Michaels response.

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Just tried it with the free Autodesk 123 Design and while it requires a bit of
clicking, for selecting the individual parts, it works there too.

Regards
Stefan

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Hello,

i just test it with diverse subsets and get after a long time a solid from all parts (moi beta4).
the resulting 3dm of this solid got over 30mb. Maybe a hint, whats going on?

best regards,

tijai

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Hi Alex, boolean union in MoI can sometimes get confused with a large set of objects like that if it happens to try and union together 2 non-intersecting pieces to start with.

So in a case like yours you can get the boolean finished in MoI if you do it in smaller steps.

You'd need to start out with 2 crossing pieces like this:



Then by progressively moving down along that diagonal adding 2 more crossing pieces at a time I was able to successfully boolean everything in MoI.

MoI automatically sorts objects that are processed in boolean union so that the largest and smallest pieces are combined together, so that helps to avoid this "order of processing" problem for cases with a large base object being unioned with smaller pieces sticking out of it but it doesn't help in your kind of situation here.

I have it on my list to investigate exactly why Solids++ is sensitive to the processing order for boolean union and it's probably solvable but I expect it to be a time consuming investigation and so it won't happen in the v4 time frame.

- Michael

Image Attachments:
Alex_boolean_union.jpg 

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I Draw a line of 10 tubes
I draw a line of 70 tubes perpendicular

Union All maybe 15-30 seconds
Cut by a line above the line of 10 tubes

Select all
Draw a line of 6 copy of the "selection"

Select all
Boolean Union - 2 minutes

Total times elapsed 2.15 minutes or maybe 2.30 (i7 - 2014 windows 10)
so 4900 tubes intersections / Unions as result

155 megas (3dm): Challenge is open! :)

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Hi,

I selected all, then clicked join,
then I selected all, clicked boolean union and about a minute later it was done,
worked like a charm.
Win 10, 16 GB memory, Intel I7-4820 MoI V3 trial

Image Attachments:
test.jpg 

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Hi All, thanks to all for your various insights extremely helpful - as always the MOI forum a gold mine full of talent.

best regards
Alex.

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@death

wow that's interesting. i will have to remember that trick if i run into an issue like this. i never would have thought to try just joining surfaces before a boolean op.

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Join actually has no effect on objects that are already solids.

- Michael

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Well, whatever the side effect is, it works for me, 52 seconds flat!

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