Boolean Intersection of Surface Extrusions (Curved)

emil_4

Dear Onshape Developers,

Any chance of adding capability of doing boolean intersection of surface extrusions (results in a curved line)?  Boolean intersections only seem to work with parts.

lougallo

@Emil I have logged this.  It is a very common practice to do an intersection curve like this to generate complex paths for sweeps and other geometry.

emil_4

Thanks!

fastwayjim

Hi @LouGallo ! Can you add me to that ticket please? We were discussing this in another post (here). Thanks!

andrew_troup

+1

also another highly desirable capability: Cut with surface

("extrude cut from surface" would be a workaround, once you get round to adding a "from" condition, as well as a "to" condition, to extrudes ... but it would require creating a sketch, and probably a plane)

abefeldman

@Andrew_Troup and @FastwayJim - Added you both to the improvement.

@Andrew_Troup, can you elaborate a bit more on your 'cut with surface' request?  While our surface generation tools aren't very mature yet, we do allow you to split parts using surfaces.  Is that similar to what you're asking for?

andrew_troup

@Abe
OK, I can split using my surface, and then delete one of the sub-parts. Thanks a bunch!

That's a pretty satisfactory workaround. It might be even better (and eliminate the need for a "Cut with Surface" tool altogether) if I could choose which parts to keep, to simplify the feature tree. I wonder if there is merit in OnS automatically renaming features when a 'versatile' tool is used in different ways? So that "Split Part" might become "Cut Part" if only one component was kept, and "Split/Cut part" if not all components were kept.

This might seem a lot of trouble to go to, but in the case of Split Part, there is currently no visual indication, when using rollback, that anything has happened. Perhaps new colours could be allocated to newly created parts?

Solidworks went part way there with the "Offset Surface" tool; if you specified zero, the Title bar description would change to "Copy Surface" (but, perplexingly, the FM tree description did not!)

Particularly if the OnS tree remains purely textual, it seems to me the default descriptions need to be enriched. At present I cannot tell from the tree whether Extrude 1 is a solid, or a surface, or a cut-extrude, or an intersection, or some combination.

Personally my preference would be for that information to be captured with a combination of text and other cues: it's simply too slow and klunky to have to read each line in order to orient yourself to the tree, even before you start to extract meaning from it.

Eric_52

Was the intersection sketch of two surfaces added as a feature?  It is one major thing holding me back from switching to onshape from solidworks.

michael_hwang

Was this ever added?  I'm halfway through my model and I need to make a curve like this, but now I'm stuck.  I thought this was trivial so I didn't check for this capability beforehand...

konstantin_shiriazdanov

@michael_hwang there is split comand that makes intersection edges, and composite curve feature that makes a wire body from the set of connected edges

owen_sparks

And the projected curve...

MBartlett21

Try this boolean feature:
https://cad.onshape.com/documents/84d939daceef6a928b8abcba
It takes parts, surfaces or faces as input.
If you input two surfaces with intersection selected it will generate a curve

billy2

You're tearing these surfaces and leaving the extensions up to some algorithm. Other than that, you can split'm. This gives you an edge (which is a curve) or you can delete one of the bodies (which is a trim). This isn't real obvious, could be better.

We need good knit and unknit tools. If you have trimmed surfaces, you have to use enclose to knit which is way more than it should be.

This said, it takes a little work, but you can get surfaces to work.

MBartlett21

My feature only calls opBoolean using definition.
It sets allowSheets to true and eraseImprintedEdges to false for a surface intersection.
It doesn't work if it should create two curves (see https://forum.onshape.com/discussion/9239/opboolean-on-surface-bodies)