Accessing Mac's GPU in Parallels5?

I'm running a video app called vReveal on Windows 7 in Parallels 5, on an iMac with an Nvidia GeForce8800 GS gpu, but vReveal keeps saying it can't access the GPU and that is why processing is slower than it should be.

Is there any way to allow apps running in Windows to access the Mac's GPU? I've seen a few similar questions in the forums, over the last couple of years, but never any answers... so far.