Create a 3D PDF of Autocad 3D Drawing without losing colours?

[owlie]

I have a fairly simple 3D drawing made in Autocad 2012. It has 3D solids all of the same material type.

 

I want to import it into a 3D PDF. So far I done the following:-

 

- I have got Adobe Acrobat Pro XI on a free trail basis.

- Open Autocad drawing in Inventor Fusion 2013.

- Save as .step file

- In Adobe select create new PDF.

- Bring in the step file.

 

My problem is the 3D drawing appears in the 3D PDF but all colours are lost.

 

I have the following software on my machine:-

 

Revit Structural 2012 and 2013

Inventor Fusion 2013

Autocad 2012 and 2013

Navisworks Manage 2012 and 2013

Autocad Sketch book designer 2013

Autocad SHowcase 2013.

 

Is the problem when the file is 'saved as' in Inventor? Or is the problem within Adobe? I have brought in other .step files as a test and they appear normally, but the problem is I don't know what software was used to create them (the step files came externally).

 

PS I don't use Inventor normally, but we have it as part of the Plant 3D Suite on our machines, so I don't know if there are settings in Inventor that need to be changed. If you have any suggestions that involve changing things in Inventor - please make them simple as I am rather simple with Inventor ;)Hope you can help. Thank you.