Hallo!
Just started with blender.
Is it possible to create a curve along a mesh (I don’t think so) or along a surface spanned from two or more curves?
Thanks!
hi, you can select needed Edgeloop from the mesh surface, then copy it by SHIFT+D and moving it somewhere. Separated edgeloop you can convert to Curve by staying in Edit mode and running python script ‘Edges to curve’ (Menu: Mesh/Scripts/Edges to curve). Your new bezier curve will be created and placed over edgeloop with 3D option enabled
Hello HadesVsPluto,
You can draw curves directly on a mesh using Retopo.
Lets say you wish to draw a curve on a sphere.
Create your sphere and then create a curve in front of your sphere,
the Retopo tool is view dependant so make sure it is in front of the
sphere in your viewport.
Making sure you are in edit mode of your curve click the Retopo button
under Curve Tools1 then retopo all… your cursor should become a ?
then you click in the current viewport and your curve should be projected onto
your sphere. You can now edit the curve and also add new parts to your
curve all staying on the surface of the sphere.
Hope this is helps?
Rgds,
P
Thank you both 
!
I’ll try.
No problem let us know how you get on.
Rgds,
P
it works fine! 
both!