Why does the Part --> booleans returns Compounds

[bernd]

Hi,

Does someone know why the part --> booleans (cut, union, intersection) on solids returns compound containing the resulting solid?

Is there a possiblility to return solids instead of compounds, or is there a parametric way to get the solid out of the compound?

Bernd

[NormandC]

I'm not sure why it does that, but one of the devs (maybe Werner?) told me that if the compound contains a single solid, you are fine. I stopped caring after that advice.

The Fillet operation also quite often produces a compound.

[wmayer]

Up to my knowledge boolean operations always returned a compound independent of whether it's a single solid or a million. Thus it's up to the caller of the function to unpack a single solid if this is what he expects.

In Python it's very easy:

Code: Select all

result = ...
solid = result.Solids[0]

[bernd]

Up to my knowledge boolean operations always returned a compound independent of whether it's a single solid or a million. Thus it's up to the caller of the function to unpack a single solid if this is what he expects.

Code: Select all

result = ...
solid = result.Solids[0]

This python snippets is exactly what I would like to get rid off because it is not parametric and it is not in user GUI.

Does it make sense to create a mantis for a new preference for part. A small wrapper around the part booleans. If a boolean returns one solid in a compound the solid is returned instead of the compound. The resulting object in FreeCAD tree would than be a solid.

[jmaustpc]

Up to my knowledge boolean operations always returned a compound independent of whether it's a single solid or a million. Thus it's up to the caller of the function to unpack a single solid if this is what he expects.

Code: Select all

result = ...
solid = result.Solids[0]

This python snippets is exactly what I would like to get rid off because it is not parametric and it is not in user GUI.

Does it make sense to create a mantis for a new preference for part. A small wrapper around the part booleans. If a boolean returns one solid in a compound the solid is returned instead of the compound. The resulting object in FreeCAD tree would than be a solid.

At one time in FreeCAD, a Part Fuse output would be invalid if the Fuse did not create a single solid. My understanding was that the creation of a Compound from a fuse is so that a fuse of more than one non-intersecting solids would be able to give a valid output.

If you are going to do something with the solid from a Fuse, you would need to first check that there is only one solid in the Fuse output compound.

[bernd]

At one time in FreeCAD, a Part Fuse output would be invalid if the Fuse did not create a single solid. My understanding was that the creation of a Compound from a fuse is so that a fuse of more than one non-intersecting solids would be able to give a valid output.

If you are going to do something with the solid from a Fuse, you would need to first check that there is only one solid in the Fuse output compound.

Sure I'm only talking about the cases when the result is valid and only one solid. Ahh thats exactly the problem how to distinguish. I see ...

[bernd]

Found it !!! Lattice2 has exact the tool I need, hopefully! It is called "CompoundFilter remove some childs from a Compound!

[bernd]

For the last two month I have been using the tool CompoundFilter from lattice2 really really a lot. I would vote for integrating this tool in FreeCAD master? How about others?

@DeepSOIC:
What do you think about this?

bernd

[DeepSOIC]

For the last two month I have been using the tool CompoundFilter from lattice2 really really a lot. I would vote for integrating this tool in FreeCAD master? How about others?

@DeepSOIC:What do you think about this?

Actually, that was the second tool added to Lattice, and I was considering to merge this tool into FreeCAD from the very beginning.

Do you have a good suggestion as to where the tool should be? What workbench?

[triplus]

As workbench is more or less organizational structure and the basic unit is the tool itself i guess choose one of the Python based workbenches or just add Lattice to FreeCAD by default.