Ask Slashdot: Why Don't Graphics Cards For VR Use Real-Time Motion Compensation?

dryriver writes: Graphics cards manufacturers like Nvidia and AMD have gone to great pains recently to point out that in order to experience virtual reality with a VR headset properly, you need a GPU capable of pushing at least a steady 90 FPS per eye, or a total of at least 180 FPS for both eyes, and at high resolutions to boot. This of course requires the purchase of the latest, greatest high-end GPUs made by these manufacturers, alongside the money you are already plonking down for your new VR headset, and a good, fast gaming-class PC. This raises an interesting question: virtually every LCD/LED TV manufactured in the last 5 or 6 years has a 'Real-Time Motion Compensation' feature built in. This is the not-so-new-at-all technique of taking, say, a football match broadcast live at 30 FPS or Hz, and algorithmically generating extra in-between frames in real time, thus giving you a hyper-smooth 200-400 FPS/Hz image on the TV set with no visible stutter or strobing whatsoever. This technology is not new. It is cheap enough to include in virtually every TV set at every price level (thus the hardware that performs the real-time motion compensating cannot cost more than a few dollars total). And the technique should, in theory, work just fine with the output of a GPU trying to drive a VR headset. Now suppose you have an entry level or mid-range GPU capable of pushing only 40-60 FPS in a VR application (or a measly 20-30 FPS per eye, making for a truly terrible VR experience). You could, in theory, add some cheap motion compensation circuitry to that GPU and get 100-200 FPS or more per eye. Heck, you might even be able to program a few GPU cores to run the motion compensation as a real-time GPU shader as the rest of the GPU is rendering a game or VR experience.

So my question: Why don't GPUs for VR use real-time motion compensation techniques to increase the FPS pushed into the VR headset? Would this not make far more financial sense for the average VR user than having to buy a monstrously powerful GPU to experience VR at all?

Comments

Sickening

[bobbutts]

I find the effect sickening on a flat TV. I'd gather it's worse in goggles.

Re:Sickening

[Anonymous Coward]

There are, however, things that make VR implementations easier and less error prone.

If the VR helmet itself, which has motion sensors, detects motion, it could apply motion compensation while it awaits for a new frame.

The approach could be limited to head movements, be truly helpful and nigh flawless if done correctly.

So really, the poster does make a valid point.

Re:Sickening

[Martin Blank]

It reminds me of the Hobbit movies, in particular of the battle on the river. I was taken out of the movie by the splashes. They looked fake, but I knew that this was more because the movie was shot at 48FPS and so captured the motion better.

So does it look fake because it is fake, or does it look fake because it's different from what we expect to see?