Re: hw antialiasing in OpenGL

New Message Reply Date view Thread view Subject view Author view

Simon Bennett (simonb++at++wormald.com.au)
Fri, 14 Feb 1997 15:27:17 +1111 (EST)


On Thu, 13 Feb 1997, Joseph Paul Mancewicz wrote:

> I need to know how to obtain the hardware antialiasing that you can get
> performer but using OpenGL. The
> glBlendFunction/glEnable(GL_POLYGON_SMOOTH) route seems to tap the
> hardware, but requires front to back ordering of the scene. Is there a
> way to get fast (interactive speed i.e. not dependent on an accumulation
> buffer) hardware antialiasing in OpenGL that does not require scene
> ordering?

As mentioned before you'll need to be on hardware which actually supports
multisampling (always a good start!) - so give up if you're on an Indy :)

If you are however using an RE or iR then....

Make sure you get the right visual. Call glXChooseVisual() with
GLX_SAMPLES_SGIS in the attr list and the number of samples you want.

Multisampling should then be enabled by default. Check with:

    glIsEnabled(MULTISAMPLE_SGIS);

and turn on/off with:

    glEnable(MULTISAMPLE_SGIS);
    glDisble(MULTISAMPLE_SGIS);

You can also fiddle with the sample mask and stuff if you want. Note that
this is an SGI specific extension to OpenGL.

+----------------------------------------------------------------------------+
  Simon Bennett simonb++at++wormald.com.au
  Wormald Technology Advanced Systems Engineering Ph: +61 2 9981 0669

                "Good judgement is the result of experience.
                 Experience is the result of poor judgement"

=======================================================================
List Archives, FAQ, FTP: http://www.sgi.com/Technology/Performer/
            Submissions: info-performer++at++sgi.com
        Admin. requests: info-performer-request++at++sgi.com


New Message Reply Date view Thread view Subject view Author view

This archive was generated by hypermail 2.0b2 on Mon Aug 10 1998 - 17:54:39 PDT

This message has been cleansed for anti-spam protection. Replace '++at++' in any mail addresses with the '@' symbol.