Editing Weapon Idle Position

Using VFX Editor to Offset Weapons on Idle Stance

Before you start, make sure you have the VFX Editor plugin for Dalamud (as well as using XIVLauncher to run Dalamud). You will also need Penumbra to implement the mod if you do not want to load up VFXEditor all the time.

Step 1 - Open VFX and Select ATCH:

Open up VFX Editor by typing /vfxedit. Proceed to click the “atch” button.

Step 2 - Select Race and Gender:

In the new window, under Loaded Atch (the first line), click the Search button, and in the new window, select Character, then select base Race/Gender. Pick you character's race/gender, then hit Select.

(For this example, this guide will use Hyur Midlander F)

Step 3 - Select Weapon/Tool/etc:

A new list will pop up on the Atch Editor window (you can close the Atch Select [LOADED] window).
This contains a list of all weapons, tools, and other related things. Please refer to the bottom of the guide to see which affects which classes/jobs.

Step 4 - Select Replaced Race:

Below "Loaded Atch", on the line Atch Being Replaced, click that search button's icon, and repeat step #2. This is for the one you want to load to. Use the same choice as you picked for Step #2

Step 5 - Select the Weapon:

Now with the job or class you want weapons adjusted, make sure those weapons are currently shown. Click the weapon (forehand or backhand, whichever you want to adjust) and you will see six lines that are named "State".
You want to edit State 1, and should either have "kosi" or "sebo" in the name (Kosi for hips, Sebo for back):
j_buki_kosi_<l/r> → Sheathed Weapon (Hip)

j_buki2_kosi_<l/r> → Sheathed Weapon (Hip2)

j_buki_sebo_<l/r> → Sheathed Weapon (Back)

Press the small white triangle button to expand the window of that weapon's State 1, and you should see some numbers like in the example above.

Step 6 - The Trial and Error Part:

This part will be the trial-and-error part. Change only one value (use increments of 0.1 or 0.01) at a time, then hit the green UPDATE button to see a change on your weapon. If things went well, the weapon on your character should have moved in some way…

• Focus on Offset and Rotation part. These values do not necessarily coordinate with X, Y, and Z, and this moves only one weapon for the class/job for that particular race/gender. (Offset moves placement, rotation changes weapon orientation. This affects you idle standing position with weapons sheathed.)
• Use Change Pose (in-game) to see how the weapon looks on different standing idle positions. I start at the base standing position where both arms are just straight down. (I do not know how to "reset" a value, so I write down the base numbers in case I need to start from base.)
• Save your workspace by going to File > Save As, then select where you want to save your workspace (then use Save when you make further changes). Use Open (or Open Recent) to load this up again in the future.

Step 7 - Saving it all:

Once you have made all your changes for every job you want adjusted for that single race/gender, click Export, then pick either Penumbra or Textools, then fill in the information for your modpack then Save. You can also export the RAW ATCH file as well (the button to the right of the green UPDATE button), espcially if you want to use your adjustments for other races/gender.

If you want to edit other races/gender, click the + button (see below) and then repeat the previous steps. You can keep one Workspace file if you want to adjust multiple races/gender.

Finalizing and Notes:

Turn off VFX Editor, then load the .pmp or .ttmp2 file to see if it worked (and that you do not need to load in VFXEditor each time you log into the game).

• Not all races/gender will share the same exact values for 1 weapon, will need to adjust for each if planning to do all.
• Hand collisions will occur on idle positions. Move the weapon again if it bothers you.
• Using Change Pose can make some weapons look further out/in. I tested with the standard idle position (arms straight down).
• If you use Customize+, you will need to adjust for that (load your C+ setting for your character before adjusting weapons). C+ Weapon Offset is NOT working as of now.
• If you edited one race/gender, and if you want to load those settings on another, you can save that workspace into an .ATCH file, then load that file in Loaded Atch (first line). Note that it will use the base of the loaded race/gender combination, and may not reflect the natural weapon positions of the target race/gender. This can save work, but weapons can appear farther on other races/gender, and may need more fine tuning.
• Crafting main tools will either have a side hip tool or a back tool position. (If you need to test back tools, use Glamourer and switch to an Aesthete tools)
• This guide is for adjusting weapon positions on the idle position. For drawn and everything else, I think you would need to adjust the other States (personally have not tried this).

Special Thanks to: 

ReqRider for writing the Original Guide. 
Saenomaed for Teaching ReqRider this technique.
Everyone involved in VFXEdit, especially ocealot.

ATCH Weapon Items Code List

Paladin (Gladiator)
  swd -Sword (hips)
  sld -Shield (back)
Warrior (Marauder)
  2ax -Greataxe (back)
Dark Knight
  2sw -Greatsword (back)
Gunbreaker
  2gb -Gunblade (back)
Dragoon (Lancer)
  2sp -Spear (back)
Reaper
  2km -Scythe (back)
  ebz -Reaper Shroud (none)
Monk (Pugilist)
  cls, clw -Claw (hips)
  clg -Glove (none)
    Notes: I found cls may work rather than clw, like with tonfa weapons
Samurai
  2kt -Katana (hips)
  ksh -Samurai Sheath (hips)
Ninja (Rogue)
  dgr, (dge) -Dagger (hips)
  frg -Ninja Frog (none)
  rbt -Ninja Rabbit (none)
    Notes: dge may not affect daggers, have not found a use
Bard (Archer)
  2bw -Bow (back)
  qvr -Quiver (back)
  flt -Flute (none)
  hrp -Harp (none)
Machinist
  2gn -gun (back)
  bag -Machinist Bag (hips)
  msg -Machinist Shotgun (back)
  mwp -Machinist Cannon (back)
  gsl -Machinist Deployable (none)
  syl -Machinist Sniper (none)
    Notes: Shotgun and Cannon are normally deployed quickly, may not need to adjust these
Dancer
  chk -Chakram (hips)
Black Mage, White Mage (Thaumaturge, Conjurer)
  2st -Greatstaff (back)
  stf -Staff (hips) [single hand staffs, 1.0, 2.0 content]
Summoner, Scholar (Archanist)
  2bk -Book (hips)
Red Mage
  2rp -Rapier (hips)
  orb -Red Mage Focus (hips)
Blue Mage
  rod -Blue Mage Rod (hips)
Astrologian
  2gl -Globe (back)
  crd -Astrologian Deck (hips)
Sage
  2ff -Nouliths (back)

Carpenter
  awo (back)
  saw (hips)
  csl, csr (none)
Blacksmith
  hmm (hips)
Armorer
  aar, abl (back)
  hmm (hips)
  ytk (none)
Goldsmith
  agl (back)
  mlt (hips)
  tbl, tgn (none)
Leatherworker
  alt (back)
  fry (hips)
  prf (none)
Weaver
  ase (back)
  tmb (hips)
  ndl, whl (none)
Alchemist
  aai, aal (back)
  ali, alm (hips)
  mrb, mrh (none)
Culinarian
  aco (back)
  fry (hips)
  stv (none)

Miner
  pic (back)
Botanist
  htc (back)
  nph (none)
Fisher
  fsh (back)
  fha (none)
  sic (none)

Unknown:
  Hips -rap, gun, yt2, ytc
  Back -sht
  None -atr, avt, col, cor, cos, crr, drm, egp, elg, fcb, fch, fdr, fl2, fud, gdb, gdh, gdl, gdr, gdt, gdw, gsr, hel, let, lpr, nik, oum, pen, sxw, syr, syu, tcs, trm, trr, trw, vln, wng, ypd