Sci-Fi Crate

Question Modeling



I'm trying to build my own crate and I have some minor issues. 

I can't create a loop cut (with CTRL+R) that surrounds the entire extrusion. In the image above I want to extrude along normals (ALT+S) not just the front part, but the entire structure. I tried using the knife tool, but it doesn't connect those 2 edges. 

  • Omar Domenech replied

    When a loop cut can't make it all the way through, it means you have an ngon or a triangle, interior faces, double vertices, etc. You have to try and make your mesh all quads for things to behave properly. It's difficult to troubleshoot from an image, if you want you can share your blend file for us to take a look. 

    Seems like you're doing the fundamentals of mesh modeling. Remember, you can always go back for refreshers and watch previous lessons. Also you can take a look at other modeling courses like these one:

  • Martin Bergwerf replied

    Like Omar said:


    Don't know why the Knife Tool wouldn't work.

  • Roxana Moise-Dan(ox) replied

    OOmar Domenech I know why the loop cut doesn't work, I just don't know how to fix it. The problem for me is that I can't think 3 steps ahead and I find myself in situations like these, where the geometry is not right, but don't have a solution.  I will check that course also.


  • Martin Bergwerf replied

    Hi Roxana, thanks for the file!

    Try the old M > Merge > By Distance trick.

    Then the Knife Tool works and If you select these Edges:


    and X > Delete Edge Loops, The Loopcut goes further, untill it hits this triangle:


    Note, I pushed the white Edge back along the X-Axis a bit to reveal the Tiangle, that originally had a surface of 0, also known as a Zero Face.

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  • Martin Bergwerf replied

    If you make it like this, the Loop Cut will go around:


    And over time, you will learn to think a few steps ahead, don't worry.

    1 love
  • Roxana Moise-Dan(ox) replied

    Thank you! It works now. 

    One solution I found on google is that I can triangulate the Ngon and then transform it into a quad (ALT+J) but it didn't do the trick. Do you think maybe in other cases this is a valid answer? I think what I want to know is if it's possible to fix Ngons when you're so far along the way that is not possible to undo a bunch of times, while also being able to create a loop cut.

  • Martin Bergwerf replied

    There are probably some cases where that solution might work, but it's not a general solution. I have never used it myself.

    I'd say, it's always possible to 'fix' N-Gons, or Topology in general, so that the Loop Cut goes where you want it to go. I often prefer doing that, because undoing can also undo some good work you've done; it depends on the situation and your own preference/style.

    1 love
  • Roxana Moise-Dan(ox) replied

    Understood, thanks!