Random lines on part

Is it a facet type model where the curves have been converted to small flats (like stl) or triangles? If it is, those are actual physical “edges”, so display isn’t wrong. 

If you output a STL file and now see weird stuff, perhaps you just need to repaint:

https://support.ptc.com/help/creo/creo_pma/r9.0/usascii/index.html#page/fundamentals/fundamentals/To_Repaint_the_Window.html

The input is missing details. Can you attach how it looks? Process of generating the CAD? those details will help the others to understand and get a better solution to your problem. 

Hi ​@TV_12110732,

I wanted to see if you got the help you needed.

If so, please mark the appropriate reply as the Accepted Solution. It will help other members who may have the same question.
Of course, if you have more to share on your issue, please pursue the conversation.

Thanks,
Anurag