How do I fix this irregular shading on my subsurf retopology attempt?

Question

So I am retopologizing an elbow on an arm mesh, but there is this strange vertex that just sticks out of the mesh whenever I use a 2-level subsurf modifier with smooth shading. Here are some photos:

Vertex is in dead center of elbow:

The mesh with the vertex highlighted:

Is there a quick way to make this stubborn vertex conform with the rest of the arm, or do I have to just sit and continue to rearrange my mesh?

Answer 1

Add additional edges with the Knife-Tool K.

• Select the vertices of the elbow joint with Box Select B.
• Delete the vertices X.

• Select the edge rings and search for Bridge Edge Loops Space.

• Recreate the mesh using Inset I with the faces selected.

Alternatively (recommended) you could use 'Diamonds' to bridge from 16 to 8 vertices edge rings as described here: Are there more standard patterns besides diamonds which will preserve quad only meshes?

Answer 2

you have nGons which tends to cause problems for both sub-division modifiers, animations and texture baking.

For hard-surface/mechanical type models, you can use tris/nGons on flat areas so long as the transitions to curved areas are all bordered with quad based geometry. Note this will still make some of the selection tools less effective.

The following chart shows many ways of redirecting polygon flow so you can keep an all-quads mesh that has clean lines that will still work well with various modeling tools.

Credits: The authors name can be seen at the bottom of the image.

I have found half a dozen charts like this so you might want to do some more digging using keywords such as "polygon flow" "quad modeling" as the basis for an image search.