Daverave,
You are right, but my problem remains solid.
What I was tring to get was UV seams from those curves. but it's not exactly going to help me.
My goal is to, in Unreal engine, make a simple sphere and apply a "simple" rectangular texture and deal with normal maps instead of modeling a precise volleyball.
In a lot of tutorial, people juste take a picture like this one :

and apply it on a sphere and it nicely goes wraping around it.
Now what if I don't have this image ? How can I create a texture that once wrapped around will make thoses shapes ?



First I thought I would make a Mapping transformation, I managed to get curves in excel like theses :

but then I realisez that I would not be able to get correctly the "dotted" texture of a mikasa volleyball if I directly go to photoshop.

I...really don't know how to do this. Like you said, i don't even know where to grab that stick.