Hello again,
I would like to use booleandifference in a way that regardless of the cutting object going through more than one solids it only obstract from one solid.
Unfortunately it keeps on failing and I am unsure how as it is such a simple things…
Any advise how to do it?
I have clicked on all the ! marks but they do not makes sense…
green solid - I would like to substract with
red solid - I would like to substract from
thank you!
best is always to post the 3dm file containing the parts that fail, otherwise it’s guesswork to say what’s going on. that being said, run Intersect on the two objects and see if you get a single closed loop. If not, well, post the file…
Hello Gijs, Thank you! I run intersect, it showed me two curves but I do not unfortunately know what to do with it or how that will effect the booleandifference command.
I attached the file. Thank you!
building practice.3dm (3.1 MB)
Hi Lili,
It’s important when doing Boolean operations that all involved polysurfaces are closed and manifold.
If not, Rhino can not evaluate where inside and outside is, and thus can’t do Boolean operations.
This one is non-manifold:
And this one is open:
You can use the ShowEdges command to display naked (around an opening) and non-manifold edges.
@Lili_A - NonManifold = there are three faces coming together at one joined edge
There shiould normally only be two - the vertical one here is 'internal ’ to the volume and should be removed, though mind what happens at the top as well -
-Pascal
Thank you very much Pascal and Diff-Arch.
I will pay attention to these and will try to close the polysurface.
So much to pay attention!
@pascal this example shows how difficult it can be for people just starting with Rhino. There are so many cases where booleans can fail, and so little feedback is given. The exclamation marks could be more informative. Rhino could indicate that some of the objects are problematic, it could show the fact that no unambiguous intersection was found, just to name a few options.
I wanted to ask you both if you know of any source that could explain solutions to the problem of offsetting,extruding,moving surfaces and the ambiguous lines of the original objects/surfaces that are left behind after them?
In the youtube video the teacher is using the gumball to extrude and I am suspecting that it might be the quickest but not the cleanest way?
Whenever I extrude with the gumball the extruded surface comes out as a seperate surface from the original that doesn’t seem sufficient if I wanted to use it as a cutting object or offset it.
x
If you have a flat surface, Extruding it with gumbal is perfectly fine:
But notice what happens if you have a curved surface:
In that case you probably want to use _OffSetSrf instead, to get even thickness:
Note that only dragging on the little round icon on the gumbal invokes an extrusion:
Hi Lili - I guess it would be best to have one or two spedific examples, as Rhino files. As Gijs points out, it can get fairly ‘technical’ when combining or editing polysurface objects, solutions or explanations are not necessarily all that user-friendly. There is information on the dots that show up, if you select one and look in Properties - it may be crypic, but it we can help you decipher…
It can pay, depending on the case, to go back and deal with the surfaces rather than polysurfaces - Boolean operations are in effect shorthand for trimming/splitting/deleteing/joining and sometimes it is easier just to do that at the surface level.
But post some examples that illustrate your questions and I’ll do my best.
-Pascal
Thank you very much both, you are very kind! I am just continuing my practice and will post a few examples.
I really appreciate your help!
