making a Pressure -Temperature-Concentration phase diagram

Hi,

1) Is there is an easier way to build a 3D diagram ( P-T-X  ) in Igor Pro: if so which one?
because for the moment the only one I have found is this Gizmo.

2) I have a path located   x=10, 20, 30 planes in a Gizmo plot. 
Question is, how to fill the area between this path, to have something that looks like in figure  

 

Thanks

3D_diagram

I think you need to give us a bit more information about what you're trying to achieve.

In the figure there are points, paths and surfaces. It sounds like you have some points and want to construct surfaces. How that should be done depends on what you know about your data. If you don't care about the thermodynamics you may be looking for some kind of 'best fit' or triangulated surface, otherwise you may have some appropriate function to describe the surface.