Can't get smooth surface when subdividing selected faces of an object I am new to blender and 3d design in general. I have a model which has smooth curved surface but the edges are not round. So I like to subdivide the faces to get a smooth shape.

When I select the faces and use Subdivide smooth I lose the smooth surface. I have tried any options I could see such as smoothing the vertexes, smoothing the faces and etc under the Shading tools, recalculating normals and almost all the uv mapping options with no luck.

What is interesting to me is that if I create a new Ico Sphere and make the faces smooth under shading and then select some faces and subdivide in the same fashion, the surface remains nice and smooth.

I also read about using subdivision surface modifier, but that one seems to only do whole object and not just selected faces in my case.

Any help would be much appreciated. Thanks!
In the edit mode with the vertex selected go to vertex panel at right hand and uncheck auto smooth



With the vertex selected go to tools panel under mesh tool click smooth vertex



Then convert the tris to quad go to Mesh > faces > Tris to Quads (Alt+J)