Creasing with subsurf and pole artifacts



I have this part of a mesh that you can see in the picture. It has exactly the shape I want, however it show nasty shading artifacts on some vertices, circled in red. Increasing the subdivisions won’t help. As you can see in the wired view, these artifacts happen to be where there are 6-sided poles, which is most likely the cause. However, I don’t see how I can avoid them while maintaining this exact shape. There is no way I can make those sharp insets with proximity loops without causing issues in the rest of the mesh, which must remain smooth. Any ideas?

Don’t use insets. Use loop cuts and crease them like this:


But this is only part of my mesh. It continues on Z. If I make loop cuts, those are going to show higher up where they are undesirable. Here is a more complete view of the mesh:


Here is the blend file if somebody needs to take a look at it: http://pasteall.org/blend/index.php?id=43537

Could do it as separate object and save a lot of geometry and hassle because of the density difference between the detail and geometry around it.
insets_ja12.blend (207 KB)

Actually you can avoid this i think while keeping same shape. You just need where the edge data and crease options on the N panel to decrease crease value for only those small joined edges at the selection shown on your screen. So just select this few small edges and set crease to 0.2 or 0.3 or remove it completely from them and it will definately smooth it. So this artifacts caused by crease value which is set too high

Silverland, that won’t work without leaving rounded mesh overhangs at the joints where the faces extrude inwards. He needs to add more edges one way or another in order to disperse the artefacts and smooth out the transition from flat surface to rounded surface.

With my method, you can dissolve the extra edges that aren’t affecting the way the mesh forms around the ‘windows’. Those faces that form that part of the object are flat, so they can contain the crease ends without creating artefacts. You just need to make sure the ends of the creases don’t reach all the way to a curved surface.

I’m looking at the blend file and I see you have subsurf cranked up to level 4. Why? That gives you way over 136,000 verts. Take it down to level 2 and you’ll only have 8,545 verts. You’re essentially adding 128,000 verts to avoid making a few loop cuts.

Anthony Forwood

I just checked the Blend file and yes indeed it creates rounded artefacts. I couldnt see it because this guy adjusted edit cage to the modifier result for some reason so it was hard to see whats going on from image. But still he can remove those creases and add two edges at the corners by using knife tool and its smooth everything. So there are many ways how to do it


so after removing small edges creases he can add two small edges here by using knife tool and it will be no rounded corners

There ya go!

Hey, guys thanks you so much for talking the time to reply, sorry to come back so late on this.

Could do it as separate object and save a lot of geometry and hassle because of the density difference between the detail and geometry around it.

I’m aware this is the simplest method however I wanted to avoid the sharpness that would result from this.

I’m looking at the blend file and I see you have subsurf cranked up to level 4. Why? That gives you way over 136,000 verts. Take it down to level 2 and you’ll only have 8,545 verts. You’re essentially adding 128,000 verts to avoid making a few loop cuts.

The reason it’s subsurfed that much is because I was doing some tests on it to diagnose the problem and see what settings made the problem better/worse, and it simply happens I left them on these setting when I uploaded the file. It didn’t mean anything.

I just checked the Blend file and yes indeed it creates rounded artefacts. I couldnt see it because this guy adjusted edit cage to the modifier result for some reason so it was hard to see whats going on from image. But still he can remove those creases and add two edges at the corners by using knife tool and its smooth everything. So there are many ways how to do it

This is a good idea however it results in ngons. The object will not deform so this is completely acceptable for me and does solve my issue, but for the sake of asking, what if it were to deform? Is there to way to model this as a single mesh without either artifacts or ngons? If this were for an animation, would I have to change my model because no acceptable topology suits it? Basically I’m just asking at large out of curiosity. We sometimes have the impression that you can render anything you can imagine, but are there some cases where one has to scrap an idea because of topology? Or is this simply a software limitation?