maintaining wanted curvature when subdivided in 3ds max

random_modeler

If I wanted to subdivided the one in left of the image(A), to the one in bottom-right(C) what should I do ?
when A is subdivided, it has jagged form just like the on in top-right(B)
I subdivided A without missing 3 polygon to establish curvature and then put edit poly on it, then manually deleted polygons(which is not what I wanted)

oglu

crease the edges... or do some support loops...

Octo

Give the arc a smoothing group and give the singled out polygon a separate smoothing group and check the smoothing groups option in turbosmooth.
Edit..I think I misunderstood what you wanted..ignore this.

random_modeler

Well, I could always just add more edges but whem I close up that part, it will still have that round round shape. I'm asking if there's a way to make clean cut just like C in first image.
If your answers say no to that, I will have to use the first method I used for object C.