U3D or PRC content in your technical content

Hi All

Would like to know if any of you are using U3D/PRC/STEP/BREP or other similar formats in your technical content?. 

If yes, are you currently generating HTML output as well of the same and what are some of the challenges there. PDF output does support U3D content but how do you take care on HTML side for these 3D content.

Thanks

Amitoj Singh