Scripted TextureMap plug-ins can only extend existing TextureMap plug-ins.
A scripted TextureMap plug-in is declared by specifying the <superclass> as textureMap .
A scripted TextureMap plug-in must have at least one rollout defined.
In a scripted TextureMap plug-in, Material and Map buttons that are associated with a parameter in a parameter block do not call the button’s picked event handler. Instead, you should link the button to a parameter in a parameter block, and use the set handler for the parameter.