Channel fade LOD attributes are set in the application process. The
  existence of multisample, required for fade LOD, is tested at the
  time that the attributes are set with pfChanLODAttr. This test for
  multisample uses the application process window system connection
  (pfOpenWSConnection) or else the DISPLAY environment variable to
  select a screen for determining graphics configuration, instead of
  testing the current window of the pfChannel. In a multipipe
  environment where one graphics pipeline has multisample and one
  does not, the application process needs to have a window system
  connection or DISPLAY that points to the pipeline with multisample,
  in which case the non-multisample pfChannels will try to use fade
  LOD. In a multi-window environment, windows without multisample on
  a system with multisample will try to use fade LOD.

Some parts © 2009 Advameg, Inc.