0
$\begingroup$

I 3D scanned an object, which created a base that I want to keep but that has holes going through it. I don't mind them at the top but I want to create a (semi) flat bottom, so the object can properly "sit" on another object.

The bottom looks similar to this (the original one is much more complex of course and the holes aren't perfect circles):

enter image description here

What I've tried:

Loop select the rectangle, press alt + f - this creates a bottom that doesn't connect to the circles properly:

enter image description here

I deleted the new faces and tried this instead:

  1. Select 3 vertices each of the border and the holes
  2. Select > Select Loops > Edge Loops - this selected the edges of the rectangle and the border of all 3 circles.
  3. alt + f - this filled everything between the rectangle's border and the holes but not the holes themselves.

enter image description here

"Edge Loops" doesn't work on the circles anymore, which might be fine in this example as I can just easily select its vertices in more or less one go with the "select box" but my real object is a lot more complex and it would take a while to select all of them for just one of the holes (let alone all 3).

How do I fill the whole area, while properly connecting the vertices of the circles too?

$\endgroup$
2
  • $\begingroup$ What you are trying to achieve Will confuse blender how to work with Normals. It will generates a lot of issues. You should fill cylinder from top and bottom part separetly with some distance to be seen by blender as faces with Normals pointing out (colored blue in Normal Orientation overaly). $\endgroup$
    – vklidu
    Jul 14, 2022 at 14:06
  • $\begingroup$ @vklidu I tried to fill the holes first but then Blender won't automatically select everything around it, which leaves me with the same problem: An area the vertices of which I have to select by hand to fill it, just this time it's the area directly connected to the outer rectangle, not the inside of the holes. What do you mean with separetly with some distance? $\endgroup$
    – Neph
    Jul 19, 2022 at 10:52

2 Answers 2

3
$\begingroup$

I don't have a solution for you ... just a note.

What you are trying to achieve will confuse blender how to work with Normals. It will generates a lot of issues especially with shading.

If I understood you right you want to fill hole by face that is at the same time part of bottom surface.

enter image description here

If you enable under Overlays > Normal Orientation you can see your model is not all blue (Blue = normal direction is pointing out, Red = normal direction is pointing inside). This will generate issues in shading since blender will twist a shadow at the place of connection between (in/out face direction).

Probably that is why it is hard to fill it. Probably blender is smart enough and tries to fit that in a right way.

You should fill bottom cylinder and bottom part separetly with some distance to be seen by blender as faces with Normals pointing out.

enter image description here

To keep some distance I mean to avoid another issue - Z-fighting (face shares the same space with another face).

Answer how to close 3D scanned mesh is not simple and easy to do. I just wanted to warn you - your proposal will generates problems and is what you really need.


Helper

Probably you can find helpful addon 3D-Print Toolbox ... if you click Solid under Result you can see how many edges are non-manifold. Clicking on that result will select all these edges in viewport.

enter image description here

$\endgroup$
3
  • $\begingroup$ The actual model I need this for isn't a simple object like in the image above but it's a 3D scanned model, so editing it is quite hard because of the sheer amount of vertices. This model is kind of similar to the image but there's one difference: There aren't any vertical edges like with the cylinders, instead there's a slope that ends at the same level the surrounding rectangle ends. - kind of like a circular skate park (image). $\endgroup$
    – Neph
    Jul 20, 2022 at 14:30
  • $\begingroup$ If I slightly change the height, then the model doesn't look like the actual thing anymore and I also can't extend the outer rectangle to give a bit more height for the same reason (plus, stretched textures). I don't want to 3D print this model at the moment (I could always add a bit more height then as the texture doesn't matter), so I won't have to worry about "manifoldness" for now (plus, there'd probably be more "non-manifold" problems anyway). $\endgroup$
    – Neph
    Jul 20, 2022 at 14:35
  • $\begingroup$ I took into account it is a 3D scanned complex object (sure its always crazy to fix those surfaces). Would be helpful to share screen of your real model and mark areas you want to fill. From your screens and description I understood you want to create a closed mesh. BTW addon is mentioned not for 3d print purpose, but it selects hole edges of your complex mesh that is hard to select manually (like you already mentioned). $\endgroup$
    – vklidu
    Jul 20, 2022 at 15:42
-1
$\begingroup$

For fixing my problem, which was the opposite of yours: I needed the holes to stay there and I pressed F instead of Alt+F. For your solution try just pressing F, which is a mesh error, but that seems to be what you are trying to achieve.

enter image description here

$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .