Help with map editor background

[TheBuildingDog]

No matter how much I try the map background doesn't show in the map editor. I Have a
def
material/editor => all in a .scs archive
map
Can someone explain what I am doing wrong? Or can I get a template from you please?
rbt.mat :

material : "dry.tex"
{code]
texture : "rbt.tobj"
texture_name : "texture"

editor_data_custom.sii

# INTERNAL MEMBERS: Insert your map specification to mod_internal.
# (\mod_internal\base\def\editor_data_custom.sui)
# Modders: Use this file to add your own map specification.

bcg_map_name[]: "/map/rbt.mbd"
bcg_material[]: "/material/editor/rbt.mat"
bcg_size_x[]: 70000
bcg_size_y[]: 70000
bcg_offset_x[]: 0
bcg_offset_y[]: 0