Ether

  Ether is the space in a scene which contains no objects. The ether has two pointers which are used for creating Gas effects

  ether->sfxtype = NOSFX
  ether->sfx = NULL

The values assigned above are the default ether variables.   To apply fog to the ether you define sfxtype as GASEOUS and sfx as a pointer to a GasSFX. The GasSFX constructor requires the type of gas and a transformation which positions the gas in the scene. As the fog gas is the same throughout space it can just be postioned at the origin.

  transform gastrans;
  Transform::unit(gastrans);//The identity transform. Positions at origin
  ether->sfxtype = GASEOUS;
  ether->sfx = (void *) (new GasSFX(new Fog(1.0, 1.0, 1.0, 0.75), gastrans));

 
Figure 23: Fog in the Ether