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Direct X Quad Buffer on ATI Radeon HD4890

Posted: Wed Jun 09, 2010 4:08 am
by AndyTheAngel
Hi all!
First, my hardware configuration:

AMD Atholon X2 64bit
2GB RAM DDR2
Windows 7 professional 64 bit
ATI Radeon HD4890

I've been a proud user of free iZ3D free anaglyph drivers for months.
I've recently bought this pair of eyewear visors: http://www.sestosenso3d.com/mediastore/ ... egory_id=5" onclick="window.open(this.href);return false;

They are the same 920D model that you can found around the web with different codes in front of it: MS stays for "MediaStore", that's the italian distributor.

They said that this eyewear works in stereoscopic withouth the need of specific drivers for the visor itself. It's quite true: you juast have to plug them into the VGA port, and it works. The problem I found it's that I can't use them for S-3D for now, because ATI doesn't have specific streo drivers like Nvidia.

Testing them with Stereoscopic Player on a computer with Nvidia quadro of a friend of mine, I've found that the only stereoscopic signal that works with them is "Quad Buffered OpenGL".

So, I suppose that I need Quad buffered stero signal. The problem is that I can't find a way to have Quad Buffer on directX, and almost all of the games I play are directX, not OpenGl. Nevertheless, iZ3D OpenGl stereo drivers chrashes on my Win7 system, as you may already know. So, until they fix the problem, I can't neither play stereo in opengl, or see 3D movies with stereoscopic player...

The question is: is there a way to activate Quad Buffer in DirectX game on my ATI HD4890? Will the Opengl iZ3D drivers be fixed soon?

Hope you will help me!
Andrea.

Re: Direct X Quad Buffer on ATI Radeon HD4890

Posted: Wed Jun 09, 2010 11:20 am
by Likay
Quadbuffered opengl is a programming protocol to support 3d (requires quadbuffered graphiccards or softmods) and it doesn't exist in directx. Quadbuffered graphicmode is often used by professional cad-applications and similar to natively generate 3d. Iz3d have a license for quadbuffered applications but i don't know how it performs since i don't use it myself.
According to the specs of the glasses they only seems to handle "Field sequential 3D stereoscopic VGA signal" which is the same format as for those 3d-dvd's you can get (play the 3d-dvd in your dvd and you'll surely get 3d without any need for any software). Iz3d or any other stereodriverdevelopers does not support this mode though. In 3d-mode those glasses are only intended for use with field sequential 3d-dvd's.
I'm surprized that the stereoscopic player somehow output such format while choosing quadbuffered opengl though.

Re: Direct X Quad Buffer on ATI Radeon HD4890

Posted: Wed Jun 09, 2010 8:44 pm
by cybereality
Isn't field-sequential the same as horizontal interlaced?

Re: Direct X Quad Buffer on ATI Radeon HD4890

Posted: Wed Jun 09, 2010 10:27 pm
by Likay
In my understanding hqfs is an interlaced signal but the left and right lines in the image are "timeshifted". As cybereality says trying horisontal interleaved mode in the iz3d-driver is a good tip though. Try different resolutions as well. Final thing to try is the simple shuttermode of the iz3d driver but i don't think it's gonna work out well.

Re: Direct X Quad Buffer on ATI Radeon HD4890

Posted: Fri Sep 03, 2010 6:07 pm
by gravity360
Just do a softmod on your ATI drivers 8-)

http://forums.guru3d.com/showthread.php?t=313065&page=3" onclick="window.open(this.href);return false;

Options, it's always about the options..

Re: Direct X Quad Buffer on ATI Radeon HD4890

Posted: Sat Sep 04, 2010 4:04 am
by Likay
Good tip.
However softmodding into quadro will not make standard opengl applications and games work though. Thought this is important to mention.

Re: Direct X Quad Buffer on ATI Radeon HD4890

Posted: Sat Sep 04, 2010 10:37 am
by gravity360
true, but it works to get OpenGL Quad Buffering working for the TriDef software.

Re: Direct X Quad Buffer on ATI Radeon HD4890

Posted: Sun Sep 12, 2010 10:36 am
by BlackShark
According to iZ3D, the Open-GL Quad buffered mode is strictly reserved for the iZ3D monitor and does not work with other output modes.
It may change in the future since iZ3D has stopped it's hardware line of product to concentrate on the software, but at the moment it's still reserved for iZ3D monitors.


There is a subtle but important difference between interlaced and field sequential.
The on screen picture is exactly the same, what differs is the way it's transmitted to the display.

Interlaced is a generic term to mention the picture is composed of two different images weaved together line by line but the picture can be transmitted in any way (including as a progressive picture).
Field sequential adds the constraint of the picture being transmitted as two separate fields. (all odd lines in one package and then all even lines in an other package).



Since the only way stereoscopic player works is using the quad buffered mode, then I can conclude your HMD probably works with frame sequential input at 60Hz (not field sequential)
In the iZ3D driver, you should use the shutter mode.
The problem is that the iZ3D driver currently cannot maintain the frame sequential framerate (in this instance you need absolute constant 30fps), this means your computer and the game have to keep up with the framerate otherwise and drop will make the left and right eye views swap all the time.