VX와 VX ACE는 따로 스크립트로 구현해야합니다. 원래 아방스에 스크립트 파일이 있으나 지금은 안들어가지는 관계로
네이버 카페 RPG 만들기 포럼에 있는 VX용 안개 스크립트 링크를 달아둡니다.

http://cafe.naver.com/dd00oo/47757

님 그거 툴 강좌 찾아보세요! 그쪽에 gm봉래산님이 올린 글이 있을거에요!

# Allows you to display a fog on map. Brings back the "old" Fog feature from
# RPG Maker XP.
# 08-03-2008 (dd-mm-yyyy) ⓒ Hevendor of rmxp.org
# 09-03-2008 Edits/additions by Jirbytaylor
# 09-03-2008 (dd-mm-yyyy) Edited by Hevendor
# Version 1.2.3
# Latest update: fixed bug where fog showed over pictures
#==============================================================================

module Fog_Map_Settings
#============================================================================
# * Configure Fog numbers -> names for setup timesaving. Format:
# {fognumber => 'fogname.extension', ...}
# where 'Fogname.extension' must be the name of a fog picture and its extension
# located in the pictures folder
#============================================================================
Fog_names = {1 => 'fog.png'}
#============================================================================
# * Set maps you wish to have fogs here. Format:
# Fog_maps = {mapID => Fog number, mapID2 => Fog number, ...}
#============================================================================
Fog_maps = {7 => 1, 10 => 1, 8 => 1, 11 => 1}
#============================================================================
# * Set up fog settings. Uses (fog number => setting, ...) format
# - Opacity - Opacity of fog, ranging from 0 (invisible) to 255 (opaque)
# - Zoom - size of fog. '1' is normal not '100'.
# - Blend - 0 - Normal, 1 - Add, 2 - Subtract
# - SxSy - Scroll settings. (fog number => [sx,sy] ...)
#============================================================================
Fog_opacity = {1 => 100}
Fog_zoom = {1 => 3}
Fog_blend = {1 => 2}
Fog_sxsy = {1 => [4, 4]}
end

class Game_Map
#--------------------------------------------------------------------------
# * Public Instance Variables
#--------------------------------------------------------------------------
attr_reader :map_id # map ID
attr_reader :fog_ox # fog oX
attr_reader :fog_oy # fog oY
#--------------------------------------------------------------------------
# * Alias Definitions
#--------------------------------------------------------------------------
alias hev_fog_feature_map_update update
alias hev_fog_feature_map_initialize initialize
#--------------------------------------------------------------------------
# * Object Initialization
#--------------------------------------------------------------------------
def initialize
@fog_ox = 0
@fog_oy = 0
hev_fog_feature_map_initialize
end
#--------------------------------------------------------------------------
# * Update Fog
#--------------------------------------------------------------------------
def update_fog
if Fog_Map_Settings::Fog_maps.include?($game_map.map_id)
@fog_ox -= Fog_Map_Settings::Fog_sxsy[Fog_Map_Settings::Fog_maps[@map_id]][0] / 8.0
@fog_oy -= Fog_Map_Settings::Fog_sxsy[Fog_Map_Settings::Fog_maps[@map_id]][1] / 8.0
end
end
#--------------------------------------------------------------------------
# * Frame Update
#--------------------------------------------------------------------------
def update
hev_fog_feature_map_update
update_fog
end
end

class Spriteset_Map
#--------------------------------------------------------------------------
# * Alias Definitions
#--------------------------------------------------------------------------
alias hev_fog_feature_initialize initialize
alias hev_fog_feature_create_viewports create_viewports
alias hev_fog_feature_dispose dispose
alias hev_fog_feature_update_viewports update_viewports
alias hev_fog_feature_update update
#--------------------------------------------------------------------------
# * Object Initialization
#--------------------------------------------------------------------------
def initialize
hev_fog_feature_initialize
create_fog
end
#--------------------------------------------------------------------------
# * Create Viewport
#--------------------------------------------------------------------------
def create_viewports
@viewport4 = Viewport.new(0, 0, 544, 416)
@viewport4.z = 9
hev_fog_feature_create_viewports
end
#--------------------------------------------------------------------------
# * Create Fog
#--------------------------------------------------------------------------
def create_fog
@fog = Plane.new(@viewport4)
if Fog_Map_Settings::Fog_maps.include?($game_map.map_id)
fog_number = Fog_Map_Settings::Fog_maps[$game_map.map_id]
update_fog
@fog.bitmap = Cache.picture(Fog_Map_Settings::Fog_names[fog_number])
@fog.opacity = Fog_Map_Settings::Fog_opacity[fog_number]
@fog.zoom_x = @fog.zoom_y = Fog_Map_Settings::Fog_zoom[fog_number]
@fog.blend_type = Fog_Map_Settings::Fog_blend[fog_number]
end
end
#--------------------------------------------------------------------------
# * Update Fog Sprite
#--------------------------------------------------------------------------
def update_fog
if @fog != nil
@fog.ox = $game_map.display_x / 8 + $game_map.fog_ox
@fog.oy = $game_map.display_y / 8 + $game_map.fog_oy
end
end
#--------------------------------------------------------------------------
# * Frame Update
#--------------------------------------------------------------------------
def update
hev_fog_feature_update
update_fog
end
#--------------------------------------------------------------------------
# * Dispose of Fog Sprite
#--------------------------------------------------------------------------
def dispose_fog
@fog.dispose
end
#--------------------------------------------------------------------------
# * Dispose
#--------------------------------------------------------------------------
def dispose
dispose_fog
hev_fog_feature_dispose
end
end




스크립트입니다.
인터넷에 fog 검색하셔서 안개 사진 다운로드 하시고
런타임 패키지 그래픽 폴더에 picture에 넣으시고
이 스크립트 입력하시면 됩니다.

출처 : https://cafe.naver.com/dd00oo/47757