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jericsynrgy

Path Cut: Upper limit ?

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Is there an upper limit to the number of polygons that can be selected and used when using the KNIFE tool in PATH mode?

I was having some success deselecting portions of the Selection Set, but that was intermittent.

JPG and *.c4d attached.  It's the last polygon Selection Set.  Basically I'd like to add some edges to this selection.  The KNIFE tool displays correctly, and displays the cut I desire (within limits, ie "close enough"), but won't actually perform the cut.

Thanks for any insight.

 

knife.jpg

Clean Slate 180514a.c4d

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The problem is not that Path Cut has a maximum amount of polys (it doesn't), it's that you have double points at the same spot all the way round the model, giving you ngons, which breaks the tool. Weld these, and you should be good. However, doing a path cut here will result in unnecessary triangles because your edge flow isn't optimal / flowing properly around the border.

 

5afa7bc0e1469_edgeflow.thumb.PNG.ddae995a6cad6c1c776518e337282a30.PNG

 

Don't know if you plan to make this more curved and organic eventually, but you might wanna lose the complex pole at the center if that is the case. This one has that done and a perimeter edge loop for superior edge flow...

 

5afa5cfedc4c6_edgeflow2.thumb.PNG.562fddebf5518b73fe15d6859ca3dfdf.PNG

 

Or, you could make this with about a 10th of the polygons if you used SDS. Now the border loop can be more evenly sized with the rest of it.

This one will deform most nicely of all because the edge flow now matches the arms and is consistent across and along each of them.

 

5afa62f28c884_edgeflow3.thumb.PNG.32b9fa65b92d6ad1a555a8a9efd8f4a7.PNG

 

 

CBR

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  • Cerbera, thanks for your time as always.  You are a HUGE benefit to the community.

    Questions! & Comments:
    1)  In the 2nd picture above, how did you achieve the large, regular patch area in the middle?  Pure sweat, or some technique and/or tool?

    2)  What threw me was, the Knife UI showed a preview cutting line, but then wouldn't cut.  I don't mind that it can't do that, but it gives every appearance of being ABOUT to do that.  It's confusing when the UI seems to say "this is what we're gonna do!", but then doesn't do it.

    3)  I managed, in my cack-handed way, to get the cut I wanted, but by using Edges describing the same (Knife) Path as the selected Polys in my examples.  FWIW.

    4)  I had an SDS mesh very similar to #3, but needed to add some bevels and whatnot to the mesh, and so was freezing the mesh to get actual geometry to work with.

    5)  The intended use of this mesh will be to output to OBJ or STL and make a 3d printed object.   It still remains to spherically distort the entire mesh.

    Thanks for your help: always an education.

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  • Oh, also, could you tell me: the final exterior edge loop around #3, was that difficult to add?  How was that accomplished?

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    11 hours ago, jericsynrgy said:

    Oh, also, could you tell me: the final exterior edge loop around #3, was that difficult to add?  How was that accomplished?

     

    Jeric, once the topology / polyflow is ok, this is done with one click in the Loop Cut tool (R18+ and in Knife - Loop mode in R17 and before as far as I remember).  

     

     

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  • EDIT:  (unfortunately, I'm on R17, and Loop-Path Cut is, I believe, an R18 tool. )

    My subpatch object was very similar to CBR's except, and this is probably key, the diamond shape quad was actually AT the tip of the arm, rather than being one loop inside.  That particular step might have made subsequent modeling more difficult than necessary, and that exterior, perimeter loop is the one I was asking about "adding": if it's modeled in from the start, obviously less of a problem.

    Thanks all!

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    Sorry - I missed all your questions until just now... 

     

    1) HB modelling bundle does quad caps with 1 click, so I did that. But would have done it with a subdivided plane and stitch'n'sew if I didn't have that. As with all circular quad patches, important that you do the outermost loop with extrude so that you preserve circularity (SDS's biggest weakness is non-circular distortion)

    2) That is a bug in that version - it shouldn't show you what it subsequently can't do, and doesn't in R19.

    5) If you are 3D printing this, then topology doesn't matter and you can't use phong or subdivision surfaces, and most likely not quads either. What does matter is high poly and a closed mesh, so I'd recommend still making as I made mine, but then setting the SDS to L3 or 4 and making that editable to get your high poly mesh, which you could then triangulate (if necessary) in your printing software...

     

    27 minutes ago, jericsynrgy said:

    EDIT:  (unfortunately, I'm on R17, and Loop-Path Cut is, I believe, an R18 tool. )

    Nope - that's in 17 too. It's K, loop mode of the regular knife tool in your version.

     

    CBR

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  • Thanks, CBR:  Loop mode is there, but seems slightly different than Loop-Path.  But I'm still too clueless to pin down the difference.

    Thanks for the 3d printing tips.  I'm currently zeroing in on the OBJ export settings that Cura will need.  EG, export scale= 0.394.  Making a "Scale & Orientatino Test Object" to nail all the parameters in one swoop.

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