how do you make bending lines in wireframe model

I have been whatching these models of yours and somehow you can make lines that bends for example in this topic if you look at moving face(animation)
lines are bending also not just moving.

how can you do that??

What you’re seeing is called “Subsurfacing”

It means make a more divided virtual mesh using the current mesh as a guide.

You can get to it in Blender 2.4 by going to the mesh editing buttons and find the panel called “Modifiers”

Add a subsurf modifier and play with the settings to see the effect.