Wrong effect with SetSmooth+SubSurf

When I set this mesh to SetSmooth+SubSurf it shows a strange distortion. However it looks good with only 1- either SetSmooth or SubSurf.


See the gator’s head (above)


The head as SetSolid (above)


The head as SetSmooth looks OK (above)


The head as SubSurf 1 looks OK (above)


The head with BOTH SetSmooth and SubSurf looks pretty funky around the mouth area. What is the cause of this?

Set all the normals pointing the same way (out) Ctrl-N


Fligh- thanks for the suggestion. I always forget to do that. However in this case RecalcNormalsOutside (Ctrl-N) doesn’t have any apparent effect- the distorion still exists.

But there is a workaround: Do SetSolid | SubSurf 1 | Convert object to mesh | RecalcNormalsOutside | Set Smooth

Now it has the same level of smoothness and polygons without the distortion.

What’s strange is the distortion was only on the left right jaw area of the head. Not on the left jaw area. So I must have screwed up somehow I just don’t see it.

Did you select all of the verts before recalculating the normals? That looks like a classic normal problem.

Could also be caused by doubled vertices. Try selecting all vertices and remove doubles, and then, just to be safe, redo the correct normals.

one more suggestion: make sure you don’t have extra inner faces/edges joining the flipped vertices. the flip sides get stretched out onto the outer surface when you subsurf. so the stripe appears only when you have both subs and smooth on (just had this problem recently too)

Thanks everyone- it was 100% user error. As anogarlr suggested, I hadn’t selected all vertices before recalculating the normals