subsurf distortion

Hi folks,

I am trying to model a slipper / flip flop… Whenever I so subsurf on the sole
of the slipper it gets all weird, how do I do this keeping the sharp edge on the
slipper while at the same time smoothing out the curves.

(posting URLs to these images causes “post denied” error message - “Post denied. New posts are limited by number of URLs it may contain and checked if it doesn’t contain forbidden words”).

If anyone has a solution can you please let me know how to do it in a step by step way? I ask this because I am NEW to blender, only started watching tutorials 3 days ago.


This will depend on you mesh topography so before we can answer we would need to see the mesh. To get the links to us trick the filter by using a space or a ^ instead of a ‘.’ or something like that.

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Chances are you have a weak pole on the edge loop. This is a vertex with an odd number of edges (3 or 5) coming out of it. Where ever you need fine definition you need strong poles (2 or 4) edges coming out of it. Unfortunately if that’s the case, you can’t rotate (the faces) to make it go away, you will need to do a little topology work.

Thanks for the tips, here are the images of before and after.



Thanks in advance for your help folks :slight_smile:

You need one more edge loop in the top and bottom face planes to help the subsurf do its job. I’ll do my best verbally, but will probably need to make an example file tomorrow when I have time. Delete all the top faces. Select all the top vertices, extrude (E) and scale down a little bit (S -> SHIFT+Z to lock Z axis). Then extrude them one more time (same as before) and close the face (you can either merge all vertices to center (W -> Merge -> Center) or close the faces as you have now. Repeat for the bottom (or use a mirror modifier) and then add the subsurf (ensuring it’s in the bottom of the modifier stack if you used a mirror).

This makes perfect poles on the edge loop most subjected to the subsurf while reinforcing. You can now use an edge slide or a crease to make the edge of your sandle as sharp or rounded as you like.

So your explanation was superb… But I ended up with a few little errors, not sure what caused them…

Here is the mesh view:

I think this is the problem, but don’t know how to fix it…

But this is the final product so far… much much better than that I had before.

Thanks again for all the assistance. :slight_smile:

My quick guess is that there where duplicate vertices there so when you extruded it made two faces. If that is the case, tab into edit mode, Select all vertices (A), Removed doubles (W -> Remove Doubles), then recalculate your normals CTRL+N. Right after you remove the doubles up on the top of blender, the top header (where File, Add, Render, Help) is at, torward the right you should see a message “Removed X vertices”, I’m guessing you will have about 6.

You were right again… Thank you… Here is what it looks like now.


One last question. How to I get edges to appear on the sole of the slipper?
The slipper I am trying to model doesn’t have rounded edges so I would like to
replicate that as best as I can. So I guess my question is how do I keep the curves of the slipper outline clean and smooth while maintaining sharp 90 degree edges between top sides and bottom of the sole. ?

Thanks again.

Are you asking how to smooth out the mesh? use Set Smooth.
(ancient tutorial, but it works :))

In 2.55 it’s in the toolbox (the panel on the left side of the 3D view and if it’s missing mouse over the 3D window and press T). In there is a button “Set Smooth”.

After that it’s worth noting, select your object, go back to your subsurf modifier and play with the levels to your liking. You should only need 1 or 2. Also, now that you have your edge loops structured, you can add in edge loops in edit mode changing the roundness some (note this can also be done with “Edge Crease”). For practice sake though, two tools worth exploring and playing with are loop cut (in edit mode CTR+R) and edge slide. For Edge slide, select the edge loop (CTRL+LMB Click), then press CTR+E and you can slide it. If you have your subsurf modifier set to be able to see it while in edit mode, you can see how it effects the shape. This technique is “Subsurf Modelling” (and easy to Google for more examples if you like).

Sandle looks good, well done!