Hi Andrei,

> Is it any way to union object but leav eges, especially after extrude? For example I want to union 2 cubes
> made by extrude but I need their eges to stay in geometry.

There is no way to turn off automatic plane merging in boolean union, but there are various other ways you could use for constructing what you want there, like do 2 extrusions with caps off, then join those together and use Construct > Planar to cap that result. Or also you could start with one big extrusion that went the full distance and then use Edit > Trim to cut it with a line, then use Join to glue those together.

Basically you will want to use Join to get that kind of result rather than a boolean union operation - join only glues together edges and does not merge faces or try to intersect any pieces with each other.


> Also just for fun, is it possible to make offset to produce those extra curves on sharp corners?

There is no way set up currently in offset to generate that automatically, you would just draw in 4 lines to get that result.

- Michael