Smoothing makes a mess of faces

[changrilla]

Hi. I'm hoping there's a solution to this. I want to smooth the edge contours of a guitar body but it makes a bit of a mess of the faces. 

Edges selected: https://mgcsoft.com/Wings/EdgeFacesSelected.jpg

After smoothing: https://mgcsoft.com/Wings/EdgeFacesSmoothed.jpg

Any way of avoiding the unwanted edges. Cheers, Gordon

[kenmo]

Looking at your model it appears to be a topology issue. Too many tris and n-gons. Smoothing, sub-d, etc usually require good edge loops and quad topology. Edge loops is hard to obtain with tris or n-gons.

That is my experience from using Blender, Hexagon 3D and Silo3D. 

I have not used Wings3D for several years but I do frequently drop by to see if there are any updates or improvements in Wings3D which wetted my interest in 3D modeling.

[changrilla]

Thanks but I'm relatively a novice at this and don't really understand the terminology. It's just a plain slab, contoured as you see in the first image.

[micheus]

Any way of avoiding the unwanted edges.

That happens because the way n-gon faces are smoothed - like every boundaries vertex is connected to the face center.
Since you have a polygon with high vertices count (front and back side of the guitar body) with some peak and valley that bad topology will be generated.

So, I would recommend you to work low poly, because it's easier to control the mesh flow. You already started the object like we would expect it to be at the end.

Bellow I'm letting you just an example to help you understand why that happens and ways we can use to avoid it on smooth.

The doted green line represents how you should imagine an n-gon polygon and the way it will be subdivided on smooth. As you can see, every time we cut the n-gon face we are reducing the amount of vertices to process and changing the center for that new n-gon:


So, if you want to keep a high vertices count in a face and ensure it will be subdivided well, you need to choose good places to add edges that will keep/support the mesh in the right place:


That will resolve the issue, but still it's not a nice mesh. If you are going to use that to be 3D printed, OK - it will work. But, it's not the desirable for render or animation.

Here is an example of using the initial mesh with less density, making easier to add more details on the curve if necessary by using Edge -> Flow Connect (on the sides) and how I would define the mesh. It's not the state of the art, but I think you can get the idea.

[changrilla]

Many thanks, I understand why now. It has a high poly count as it was a trace of an image of a pencil sketch, it's hard to predict the end result with a low poly count. In this case it's for cnc machining. I was unaware of Flow Connect. Great piece of software, very fast once you get the hang of the slightly unusual LMR mouse button usage.

[micheus]

Nice, for CNC that note for 3D printing should be valid as well.
But, if you have to design anything else on the shap, like a hole or cave something, them it's a good idea do that before you smooth the piece because you can create cuts to help you place a polygon on the place to be worked.

About the density, for this use it should not be so bad for your work now you understood how to handle it. Eventually you can do what I did by removing edges that aren't that important to define the shape. When we understand how the subdivisions will be applied we like know where we can remove these edges, slide them to and so on.

Remember you can use Smooth Preview [shift + TAB] to get the Idea about how it's going on.
Also, when removing an edge it's a good idea to use the Dissolve [RMB] that will remove any orphan vertex - that avoids unwanted issues after removing edges.

[ismacou]

Hi everyone.
I'm leaving this suggestion here hoping it might be useful to you.
Cheers!

[changrilla]

Hi Ismacou. Thanks for taking the trouble to make the video although I'm not sure how that helps with the smoothing?

[changrilla]

Hi, Thanks Micheus. How does Dissolve RMB differ from cleanup with respect to vertices which I use regularly, just in case there are any unwanted vertices.

[micheus]

Hi, Thanks Micheus. How does Dissolve RMB differ from cleanup with respect to vertices which I use regularly, just in case there are any unwanted vertices.

No difference if you take care about use only the option to remove isolated vertices (RMB option), otherwise you should take care of shirt edges to not be removed.

I use to work that way preventively since I know I don't want to keep that vertex. So, barely I need to use clean option - except when I noticed in smooth preview I have left something behind. :-)