Question How to make a partial shader?

What I have done:
1.Create a 3D object Sphere.
2.Drag a png image in project window on the sphere.

Then I get a ball with albedo map shader like this:


What I want:


The standard shader make the texture image clamp to wrap the whole sphere, but I just want the image map on some part of the sphere, which looks like a poster be pasted on it.

I don't know if Detail Mask can realizes that.I've read the document of Detail Mask :https://docs.unity3d.com/Manual/StandardShaderMaterialParameterDetail.html
But I can't figure out how to do that. In addition, I hope the image can be easily changed on size and offset.

Can someone tell me how to do detail mask, or is there a easier way to realize that?Thanks!

 

You need to UV unwrap a sphere

 

Thanks! I've found a tool called UV editor to realize that.