Step 2.1) Slicing the ArtDefines.
Root Import Directory) \Mods\MyMod\Assets\XML\Art
Root Export Directory) \Mods\Celts\Assets\XML\Art
XML Editor
Open \Mods\MyMod\Assets\XML\Art\Civ4ArtDefines_Civilization.xml
Notepad or somthing
Open \Mods\Celts\Assets\XML\Art\Civ4ArtDefines_Civilization.xml
Note: You can use notepadish progs to open file you tak info FROM(Celts files) as the XML Editor will forma it for you.
In this file find
<CivilizationArtInfo>
<Type>ART_DEF_CIVILIZATION_CELT</Type>
<Button>,Art/Interface/Buttons/Civilizations/Celt.dds</Button>
<Path>Art/Interface/TeamColor/FlagDECAL_Triskell.dds</Path>
<bWhiteFlag>0</bWhiteFlag>
</CivilizationArtInfo>
Note: Notice how it is calling the Civilization and FlagDecal DDS files we copied earlyer.
With this file and a few others the modded part is mixed in aphabetically.
Cut this portion and paste it in \Mods\MyMods\Assets\XML\Art\Civ4ArtDefines_Civilization.xml
I will say only this right here, Use good practices from the start and put it at the top or bottom in you file (see rant at bottom).
To take a quick semi tangent, to the reason I had to not copy those 3 DDS files from the \Assets\Art\Interface\Button folder above. In the Civ4ArtDefines_Civilization.xml file you define the button picture to use for the Civ. In the Celts example the button is
<Button>,Art/Interface/Buttons/Civilizations/Celt.dds</Button>
But in other Mods you'll run across, say Nguni, it will look like this
<Button>,Art/Interface/Buttons/Civilizations/Nguni.dds,Art/Interface/Buttons/Civics_Civilizations_Religions_Atlas.dds,5,7</Button>
When the second ',Art/' stuff is there it doesn't draw its picture from the first ',Art/' part. As to why this is so I have not the foggyest, but there you are. Fixing this however is as easy as deleting the second part so that
<Button>,Art/Interface/Buttons/Civilizations/Nguni.dds,Art/Interface/Buttons/Civics_Civilizations_Religions_Atlas.dds,5,7</Button>
becomes
<Button>,Art/Interface/Buttons/Civilizations/Nguni.dds</Button>
As far as I've seen this works just fine, if I am missing anything just let me know.
Back to work...
XML Editor
Open \Mods\MyMod\Assets\XML\Art\Civ4ArtDefines_Leaderhead.xml
Notepad or somthing
Open \Mods\Celts\Assets\XML\Art\Civ4ArtDefines_Leaderhead.xml
Locate the section
<LeaderheadArtInfo>
<Type>ART_DEF_LEADER_VERCINGETORIX</Type>
<Button>,Art/interface/LeaderHeads/Btn_LH_Celt_Vercingetorix.dds</Button>
<NIF>art/interface/LeaderHeads/Vercingetorix/Vercingetorix.dds</NIF>
<KFM>art/LeaderHeads/Victoria/victoria.kfm</KFM>
<NoShaderNIF>art/LeaderHeads/Victoria/victoria_noshader.nif</NoShaderNIF>
<BackgroundKFM>art/LeaderHeads/Victoria/Victoria_BG.kfm</BackgroundKFM>
</LeaderheadArtInfo>
and
<LeaderheadArtInfo>
<Type>ART_DEF_LEADER_BRIAN_BORU</Type>
<Button>,Art/interface/LeaderHeads/Btn_LH_Celt_Brian_Boru.dds</Button>
<NIF>art/interface/LeaderHeads/Brian_Boru/Brian_Boru.dds</NIF>
<KFM>art/LeaderHeads/Victoria/victoria.kfm</KFM>
<NoShaderNIF>art/LeaderHeads/Victoria/victoria_noshader.nif</NoShaderNIF>
<BackgroundKFM>art/LeaderHeads/Victoria/Victoria_BG.kfm</BackgroundKFM>
</LeaderheadArtInfo>
Note: Notice the Leaderhead DDS files we copied being used.
Note: You may have to edit the <Button> tag here as we did above.
Now c/p these sections to \Mods\MyMod\Assets\XML\Art\Civ4ArtDefines_Leaderhead.xml
XML Editor
Open \Mods\MyMod\Assets\XML\Art\Civ4ArtDefines_Unit.xml
Notepad or somthing
Open \Mods\Celts\Assets\XML\Art\Civ4ArtDefines_Unit.xml
Locate section
<UnitArtInfo>
<Type>ART_DEF_UNIT_CELT_GAELIC_WARRIOR</Type>
<fScale>0.44</fScale>
<fInterfaceScale>1.0</fInterfaceScale>
<NIF>Art/Units/GaelicWarrior/Axeman.nif</NIF>
<KFM>Art/Units/GaelicWarrior/Axeman.kfm</KFM>
<SHADERNIF>Art/Units/GaelicWarrior/Axeman_FX.nif</SHADERNIF>
<ShadowDef>
<ShadowNIF>Art/Units/01_UnitShadows/UnitShadow.nif</ShadowNIF>
<ShadowAttachNode>BIP Pelvis</ShadowAttachNode>
<fShadowScale>1.0</fShadowScale>
</ShadowDef>
<fBattleDistance>0.35</fBattleDistance>
<fRangedDeathTime>0.31</fRangedDeathTime>
<bActAsRanged>0</bActAsRanged>
<TrainSound>AS2D_UNIT_BUILD_UNIT</TrainSound>
<AudioRunSounds>
<AudioRunTypeLoop/>
<AudioRunTypeEnd/>
</AudioRunSounds>
</UnitArtInfo>
Note: This file doesn't have any <Button> tag so no editing should be neccessary.
Note: You may notice that NIF and KFM files from the \Assets\art\ folders are being called.
C/p this part to \Mods\MyMod\Assets\XML\Art\Civ4ArtDefines_Unit.xml