I would like to know if someone try to implement the full scene antialiasing (FSAA) under OpenGL.
If yes, how to activate it and how to detect that it is hardware accelerated ? I’m thinking about the Voodoo 5, GeForce 2 under Windows.
I didn’t find any explicit explanations about it, only about accumulation buffer.
the drivers for both geforce, geforce2 and voodoo5 have anti-aliasing built in. (with the nvidia drivers it’s a checkbox or a slider.) in this case, you can be sure that it is hardware accelerated.
i’d consider leaving it up to the user. unless you’re doing more of a scene-based decision (for example, the way motion-blur was used in metal gear solid), and need deeper control.
In fact, I wanted that the user can enable/disable it in the application instead of using the dialog properties box. Under Direct3D for example, you can active it by yourself by setting a render state. I would like to do the same thing. Probably by detecting a glEXTension or something.
There isn’t any way that I know of to request AA on the NVIDIA cards in OpenGL… the API itself is totally unaware there is any AA going on. There are no extensions to support it.
The V5, I’m not sure. The method it uses is similar to a hardware accumulation buffer, but it’s not quite the same thing… so I don’t know if it’s exposed in OpenGL as an accumulation buffer or not. It’s probably best just to leave it up to the driver checkboxes to control AA.
For nVidia drivers, you can enable/disable FSAA through the registry…
Under NT it will be the following key :
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services
v4\Device0\OGL_EnableFSAA
If you give 1 (note : 1 might be written as 0x01000000 and note as 0x00000001 !) as a value to this key, FSAA is enabled. Otherwise it is not…
Note that the value after ControlSet (“001” here) can change. Also, I think Device0 can change.
All in all, I would not recommend to use this trick as it is not really clean for distributed applications…
If you decide to go this way, have a look at the key “OGL_FSAAQuality” which enables you to choose the quality of OpenGL FSAA. You can not do this via nVidia control panel but you can change the settings using this key…
Perhaps nVidia will come with an extension to specify FSAA quality…
Regards.
Eric
>Perhaps nVidia will come with an extension >to specify FSAA quality…
Well, i prefer to take trust the GL extensions (even sometime some are not documented on oss.sgi
I’ve just made a tool that displays the OpenGL driver informations and the list of extensions
(http://ww.worldnet.fr/~stedenis/glview.html)
You download the tool (34Kb) (v1.0) but try again a newer version should be available tomorrow (since my ftp site has one day of latency).