Why is there a difference between Trim and SDiff?

[Birk_Binnard]

I have collection of solid, closed Brep pipes created by hex arraying an extruded ruled surface:

When I Trim them with a solid Brep formed by extruding a 3D curved Loft surface I get this:

which is what I want - closed Breps.
But SDiff is slow to process, so I thought Trim would be quicker. But it gives me this:

These are not closed, and I couldn’t find a way to make them closed. So therefore my question - why are the results of Trim and SDiff so different?

[Gijs (Gijs de Zwart)]

Same behavior as in native Rhino, both ik result as in speed. But you might try the python version:

Boolean difference in gh much slower than in Rhino

The same using python / Rhino common takes 1.1 seconds (using the brep lists variant of Boolean difference) So my guess is that the current SolidDifference tool in gh uses the first implementation of BooleanDifference. Could well be the same with SolidDifference, I haven’t checked yet So this solution is actually much faster than the built in solid difference. the one that took 43 seconds takes 2.8 seconds now for substracting 24 objects from the original solid. But still it is slower than Rhin…

[gankeyu (Keyu Gan)]

Trim trims surface, i.e. split the surface based on cutting objects.
SDiff calculates the solid relations of multiple geometry.

[Birk_Binnard]

So it seems this behavior is by design and not some sort of quirk. That’s good to know. Thanks.