Controlling subdivision surfaces quality Is there a way to control subdivision surfaces quality ?
Specifically:

If I need extra geometry, I add an edge loop, but this changes the curvature and I have to manually adjust all the new vertices and doing it manually is not good
(In 3ds max there is the command Flow Connect, but I don't know if it is good)

Given a boundary curve (for example lines in a blueprint) how do I put the interior vertices of the control polyhedron to get a &quot;nice smooth&quot; surface, where &quot;nice smooth&quot; maybe depends on the application (In 3ds max there is the Set Flow command, but I don't understand how it works yet)

If I want to force a surface to be convex or concave how do I have to proced
There are some methods to do so:


Using edge crease (ShiftE);
Adding suppport edge loops (CtrlR);
Marking sharp edges (CtrlE > Mark Sharp), then add a Solidify modifier BEFORE Subsurf modifier.




Each way has pros and cons, choose one or more to meet the needs.

The above is for shaping in modifier level. However, the resolution cannot be controlled in this level. You may consider to apply modifier first, then select all elements (or particular area) in Edit Mode, X > Limited Dissolve, set the dissolve angle in F6 panel.

Tip: To select faces that are co-planar or nearly co-planar, you can select one or more faces, ShiftG > Co-planar, tweak Threshold in kbd>F6 panel.