s = vrml_Background (...)   - Vrml Background node

s is a string of the form :
------------------------------------------------------------------
Background {
skyColor          [0 0 0]
skyAngle          [0]
groundColor       [0 0 0]
groundangle       [0]
backUrl           ""
bottomUrl         ""
frontUrl          ""
leftUrl           ""
rightUrl          ""
topUrl            ""
}
------------------------------------------------------------------

Options :
All the fields of the node

Example : s = vrml_Background ("skyColor",[0 0 1]);