What's the point of Nvidia 3D Vision and AMD HD3D?

Question

Why they promote these weird technologies instead of just supporting OpenGL quad buffering?

Well they say AMD cards beginning with HD6000 support OpenGL quad buffering, yet HD3D is still what you see on the front pages (well, maybe because there is no native DirectX quad buffering support yet)...

Answer 1

Two reasons: Keeping an incentive for professional users who need quadbuffer stereo to buy the professional cards. Now with 3D Vision being pushed so hard a lot of people asked "uncomfortable" questions. The other reason was to try attempting on Vendor Lock in with a custom API, so that 3D Vision games would work only on NVidia hardware.

Similar reasoning on the side of AMD. However FireGL cards didn't keep up with the Radeons and so there's little reason for AMD to make their Radeon cards less attractive to professionals (current AMD FireGL cards can not compete with NVidia Quadros, the Radeons are also the competition for the Quadros), so having quadbuffer OpenGL support for them was the logical decision.

Note that this is a pure marketing decision. There never have been technical reasons of any kind for this artificial limitation of consumer cards.

Answer 2

Windows 8.1 supports Stereoscopic modes right out of the box, in DirectX 11.1.

AMD HD3D and NVidia 3DVision add:

1) Enumeration of Stereo 3D modes on Windows <= 8.1 (on Windows 8.1 the DirectX API provides this)

2) Sending the EDID signal to the monitor to enable/disable 3D on Windows <= 8.1 (on Windows 8.1, the DirectX API provides this)

3) Rendering Left and Right camera in an above/below arrangement -- it tells you the offset to use for the right image. Then, you use standard double buffering instead of Quad. (on Windows 8.1, this is not necessary -- sensing a pattern?)

3DVision adds the following:

1) Support for desktop apps to run in Stereo without engaging full screen mode (and it sometimes actually works).

2) Support for forcing non-stereoscopic games stereoscopic by intercepting the drawing calls. (this works most of the time -- on AMD, you can get the same thing by buying TriDef or iZ3D).

3) A NVidia-standard connector (e.g. proprietary, but common to all NVidia cards) for the IR transmitter and shutter glasses. (AMD, and NVidia can do this as well, uses the HDMI 3D spec and leaves the glasses up to the monitor company)

Note: The key feature in both cases is being able to enumerate modes that have stereo support, and being able to send the EDID code to the monitor to turn on the stereo display.