This component defines special rendering effects.
Background defines the sky colors and textures.
LocalFog simulate natural fog.
This component defines nodes that change the environment ("how all the scene content looks"). In particular it deals with fog and background features.
Moreover, see also Castle Game Engine (and view3dscene) extensions related to environment effects.
Display a 3D background (visible around the scene content) using a textured cube (skybox) around, or a gradient of colors.
Background but allows to specify
each skybox side as a texture node.
This allows e.g. using
MovieTexture to animate the background
like a movie.
Specifies global fog, making objects that are more distant blend to a constant fog color.
Fog, but the effect is limited to a group of X3D shapes.
Can be used within various geometry nodes,
to provide explicit fog densities for each point
(instead of calculating fog density based on the distance to observer).
This allows for various for effects, e.g. a fog may be concentrated at some
3D position (regardless of the observer).
Note that depths (in
FogCoordinate.depth) are sensible
only in the [0, 1] range (like allowed by the specification),
and are not affected by the
(also following the spec). Effectively, this means that
does not substitute the mere distance to the eye in the fog equation.
Instead, it specifies directly the fog intensity.
I understand that this is the intention of the spec, although the wording
is clumsy (not saying directly what "implicit depth" is —
fog input distance or fog output intensity).