Ksp reference Manual

Remarks
Only possible in the init callback.
Examples
on init
make_perfview
declare const $SIZE := 1644 {size of tga file}
declare const $NUM_SLIDES := 4 {amount of slides in tga file}
declare ui_value_edit $Slide (1,$NUM_SLIDES,1)
declare const $HEADER_SIZE := 93
set_ui_height_px(($SIZE/$NUM_SLIDES)-$HEADER_SIZE)
set_skin_offset (($Slide-1)*($SIZE/$NUM_SLIDES))
end on
User Interface Commands
106
KSP Reference Manual

---

on ui_control ($Slide)
set_skin_offset (($Slide-1)*($SIZE/$NUM_SLIDES))
end on
Try this with some of the wallpaper tga files of the Kontakt 4 Factory Library, e.g.
/Kontakt 4 Library/Choir/Z - Samples/Wallpaper/pv_choir_bg.tga
See Also
set_ui_height()
set_ui_width_px()