move vertex along the mesh surface

Hi, I need to know if it´s posible in blender to move a vertex without transforming the main volume of the mesh. The idea would be to re topologize the mesh without making any mayor changing on the surface (I know that necesary it would be at least minor changes as you are moving the planes). That it´s quite easy in a flat model as you lock the modifier in some axes; but it´s not so obvious to me how to make it in more organic or complex models. Just to ilustrate that I attach a raw eschemme of what I meaning. I would put an screen capture soon to exactly illustrate what I need to do.


you can duplicate the model, go into edit mode then hit the retopo button

you also have a script called loop tool i think from Crouch
that can displace vertex along curves using spline

so have a look to this might be usefull

happy 2.5

Thanks a lot. The duplicate and retopo work just fine for what I intended to do. I really didn´t understood how retopo works, so I didn´t knew I need to duplicate the object. Even now, I don´t know exactly how to use it in a more eficient and accurate way, but for what I´ve intended to do was enought. Thanks again.