Unable to join surfaces in curved body-open edges

hey ,
i want to build this curved body but there are a lot of open edges i can not close. I have tried to exend them and then trim/to rebuilt them by using the command blend and also to explode and them and than join them again. MatchSrf hasn’t worked out either. because i cant join the different surfaces , an offset to create a solid of 4mm thickness did’t work.
Later in the process i would like to insert a indentation like on the photo attached.

Looking forward to your feedback and
thanks in advance!

Question.3dm (206.4 KB)

Hi Carlotta - Join the surfaces, when the time comes, to get rid of naked edges - no need to do that, most likely, this early in the process but that is how you’ll close it up when all the surfaces are in place.

I’ll have a look at the indent part.


hej, thanks for your quick reply!
unfortunetly i can not join them all. only two of three. and later thats a problem because when I want to do the offsetsrf , the surface has little cuts.

Hi Carlotta - if you are offsetting to the outside (?) keep in mind that offsetting can make the surface quality and continuity less good - typically one would offset to the inside, that is, the less visible side. The file you posted, as it is, is a little loose at the surface edges - it does Join at the current file tolerance but it is not super clean - offsets would be somewhat less clean again. To fix your surfaces in the original posted file, try:

  1. ShrinkTrimmedSrf on all three - at least the middle surface has been trimmed and this gets rid of the part of the underlying surface that goes past the trimmed edge. Shrink them with control points showing to see what it actually does.

  2. UntrimBorder on all.

  3. MatchSrf at the common edges. Use these settings:

Edit: it would not hurt to run MakeUniform on all three before MatchSrf


thank you so much for your help! it worked out now. Did you find a solution on how to display the indentation on a curved body? i tried to rebuild it with curves but so far i don’t get any good results really. Is there a possibilety that i built the geometrie in the body? my idea was to build a solid, than use the command boolean difference to have the negative in my existing body and later do fillets. but that turned out quite inaccurate.
thanks in advance!

Hi Carlotta, I will make a couple of suggestions in a bit here - there are various ways to go about this.


perfect , thank you !

Hi Carlotta - that is one way that could indeed work. Judging from the image, I might do it a little more ‘fluidly’ so to speak, at the surface level - you can make it as one surface, or make the bottom , or floor, of the depression and connect it do the outer faces using a blend surface - I’ll make you a couple of examples.

@Carlotta something like these perhaps -

Question_maybe.3dm (812.1 KB)


amazing, those look really great!
that was really helpful!
Have a great start into your week