u3d

PDF 3D image doesn't move properly

I'm trying to put a 3D model into a PDF file. When I load the PDF file in Acrobat, it comes up. However, when I use the rotate, spin, or hand control, the 3D image stays in the same orientation while the camera viewpoint seems to point in different directions, so even a slight rotate will send the image off the screen unless I zoom way...

Can somebody recommend a good U3D library?

I need to put some 3D images into PDF files, and PDF uses Universal 3D (U3D) formats. I don't like the U3D Sourceforge project (basically what Intel released after the ECMA standardization effort). Does anybody know of good U3D libraries I could use? I'm using C++ on Microsoft Windows, FWIW. ...