Convert stl to prt "smoothly"

[YP_10031590]

I have a fairing model for a mini car I'm trying to make a mould of (something along the lines of https://www.youtube.com/watch?v=MAinuf5I_dw; I need sections of "inside" the fairing as the one in 00:00:15), and the thing is I only have it on stl format. To make matters worse, the mesh seems to have some... problems, as in intersecting itself in sharp turns.
I've already tried shrinkwrap, but even at "10" in level of detail it isn't good enough for the mould purpose. What I need the fairing as a solid for is so that I can extrude an object until it hits the fairing's inside face.

What I would like to know is: is there a way of getting better results than "10" in shrinkwrap? Or maybe there's a way of extruding up until the fairing without it being a solid part.

Thanks in advance.

P.S.: I've already read the forums (for example https://community.ptc.com/t5/3D-Part-Assembly-Design/Converting-STL-to-prt/m-p/365736#M8041 seems close enough, but there seems to be no solution) and found about REX, however I only have the student version of CREO so that isn't an option.

[Chris3]

In short there is no easy way to make a stl into a solid model.

Your best bet is to go back to the source of the stl and try and get a different format. You could also create curves and then recreate the surfaces from curves and then make it back into a solid model that way but that is a lot of work.

It appears that solidworks might have a chance of doing this if you know anyone with a seat of solidworks that could try for you:

https://grabcad.com/tutorials/how-do-i-convert-stl-graphics-to-a-solid-model 

[YP_10031590]

Thanks for the answer. However, the source doesn't have the stl in another format, unfortunately, and I'm pretty much trying to avoid having to recreate the object myself. One idea I have is cutting the stl in many smaller pieces in blender and then shrinkwrap each of them in CREO. Then, I would make an assembly of all the pieces. Seems like it could work.

[pausob]

Have you tried Meshlab?  It seems to have the tools for mesh repair and is able to output to STEP file which you could then import into Creo?  https://www.meshlab.net/#description