This Tutorial is for all those who want to add new graphics to the game, like those which are made public here in the TS Graphics forum

What you need are the XCC Utilities which you can find here: Modding Tools
You can find a manual how to use them here: XCC Mixing 101
A detailed description about the different filetypes which you may encounter when modding you can find here: the newbie guide in modding

Ok, lets start adding the new graphics.
1. download the unit,building,animation or miscellaneous graphic
2. check out the filetype
If it's a VXL and HVA file you can simply place them in the TS directory (there where your game.exe is placed) and TS will read them from there.
If it's a SHP you have to put it in an ecacheXX.mix file (XX being a number between 02-99)
However for a good mod it's always useful to place VXL and HVA files into an ecacheXX.mix too, so you don't mess up too much your TS folder.
For that check out the XCC Mixing tutorial and create a new ecache02.mix file (in simple words, copy an original mix, rename it to ecache02.mix and delete its content)
Then add your new unit,building or whatever into the empty ecache02.mix.

my suggestion for a good organized mod
ecache02.mix - for animations and buildings
ecache03.mix - for SHP units and corresponding art like cameos
ecache04.mix - for VXL units with their corresponding HVA and cameo

3. now that you have placed the downloaded unit,building or whatever file in an ecacheXX.mix and also made sure that this ecacheXX.mix is placed in your TS directory, you have to edit the ini files so TS knows how to use the new thing.
If you haven't done it already, extract with XCC mixer the rules.ini and art.ini from tibsun.mix or expand01.mix.
However you should follow this tutorial so you don't have any problems with adding new animations or trouble with different versions for TS and FS, since the Firestorm expansion reads also firestrm.ini and artfs.ini. (those two expand the normal rules.ini and art.ini and overwrite things with the same name or add new things)

Now that you have your rules.ini and art.ini placed in your TS directory, open them with Notepad or any other simple text editor.
Don't use TibEd, Sun2k or any other ini editor! Because they tend to mess up your inis and can never give you the full possibilities which you get by manual editing
Most of the public units,buildings etc come already with an example ini code. In this case simply add the appropriate example code to your rules.ini or art.ini.
If your downloaded thing doesn't has an example code, you can simply clone an object of the same type and adjust it so it uses the new graphic.
e.g.
your downloaded object is a VXL unit with no ini example.
-open art.ini and search for TTNK (that's the internal name which is used by TS to identify the Tick Tank; every unit has such an internal name which shouldn't be longer than 8 characters)
-create a copy of this entry (along with the few keys under it) and rename it so it matches the filename of the downloaded unit (e.g. mytank.vxl/mytank.hva, rename the copied [TTNK] to [MYTANK])
Always write the units internal name in uppercase as TS is case sensitive!

-open your rules.ini and add a new entry at the end of the [VehicleTypes] list (or [InfantryTypes] if it's an infantry, [BuildingTypes] if it's a building etc)
Don't change the order of any of these lists! Or the AI can't find the unit, building etc and the campaign missions don't work anymore. Allways put your new stuff at the end.
-search further for the [TTNK] section and create a copy of it (also along with the keys under it which belong to it)
then change the copies name to the VXLs name (e.g. [MYTANK]) and change its properties as you like.

4. save rules.ini and art.ini
make sure that the inis and mix file are in your TS folder. Start the game and enjoy the new unit, building or whatever.

About time we got a good "how to add new graphics" tutorial

Hes Alive!

Nice tutorial, thanks.

Thanks for this tutorial and links, this is what I have been looking for, thank you.