Intro to ItemFPSSettings

the ItemFPSSettings datablock has a ton of useless stuff in it. For customizing the animations, all you need are these settings:

  "transitionToAim": 0,
  "RecoilAnimation": 0,
  "IdleAnimation": 0,
  "WalkAnimation": 0,
  "RunAnimation": 0,
  "JumpAnimation": 0,
  "LandAnimation": 0,
  "ChargeCancelAnimation": 0,

Most of the time you only need to pay attention to these 2 settings:

  "WalkAnimation": 0,
  "RunAnimation": 0,

The goods (Custom Animation IDs)

For replacing animations, use the ItemMovementAnimation datablock included. It has a few custom run and walk (and eventually more) animations for you to use.

Currently, these are all of the animations:

   Heavy Run - 36
   Heavy Walk - 38
   Simple Walk - 39
   Simple Run - 40
   Fixed Handgun Run - 42
   Fixed Rifle Run - 43
   Fixed SMG Run - 44

Actually replacing animations

In order to replace the animations of a item, first find it inside the ItemFPSSettings datablock. For example, lets fix the Long Range Flashlight.

  "transitionToAim": 0,
  "RecoilAnimation": 0,
  "IdleAnimation": 0,
  "WalkAnimation": 9,
  "RunAnimation": 10,
  "JumpAnimation": 7,
  "LandAnimation": 8,
  "ChargeCancelAnimation": 0,
  "DofDefault": {
    "enabled": true,
    "focusDistance": 90.0,
    "aperture": 0.15,
    "focalLength": 1.0
  },
  "DofAim": {
    "enabled": true,
    "focusDistance": 90.0,
    "aperture": 0.15,
    "focalLength": 1.0
  },
  "name": "MediumFlashlight",
  "internalEnabled": true,
  "persistentID": 29

By default, the run animation will make the flashlight point sideways (which is a terrible piece of game design), so lets replace it with one of the fixed versions of the animations.

  "transitionToAim": 0,
  "RecoilAnimation": 0,
  "IdleAnimation": 0,
  "WalkAnimation": 9,
  "RunAnimation": 42,
  "JumpAnimation": 7,
  "LandAnimation": 8,
  "ChargeCancelAnimation": 0,
  "DofDefault": {
    "enabled": true,
    "focusDistance": 90.0,
    "aperture": 0.15,
    "focalLength": 1.0
  },
  "DofAim": {
    "enabled": true,
    "focusDistance": 90.0,
    "aperture": 0.15,
    "focalLength": 1.0
  },
  "name": "MediumFlashlight",
  "internalEnabled": true,
  "persistentID": 29

Now when running with the flashlight, the item wont turn 120 degrees to the left.

In order to change other items, you just need to follow the same steps we did for the flashlight but for whichever item you see worthy.

Note that different types of animations can be set to any of the items animations (IE Jump animation as an items walk animation)