The welding tools change behaviour?

The welding tools when I have smaller object in a bigger, overlapping.

Sometimes it will take away the samller and keep the overlap

Sometimes it will take away the smaller and remove the overlap

while pressing the same button …

How does LB make the decision ? Is there a shortcut ?

Many thanks

All of this is exaplained here:

Fantastic! Got it. well explained. Thanks very much for the fast reply.

Selection order of the objects delegates → what gets removed. Thx.

I must have missed that video in the introduction page.

For weld, it’s not order based, it’s how easily the software can determine what shapes are inside each other. When it’s ambiguous, you use Boolean Union with grouping.