Flexible Arms 1.21 - Customizing Arm Positions in Item Models

Flexible Arms is a client-side Fabric 1.21 mod that enables precise customization of character arm positions when holding items. Configuration is done through JSON model files.

Quick Start Guide

Getting started with the mod is quite straightforward. You just need to add an additional configuration block to your existing item model JSON files.

Here's an example configuration for basic operation:

{
  "arm_properties": {
    "held_mainhand": {
      "right_arm": {
        "pitch": -0.95,
        "yaw": -0.39,
        "roll": 0.0,
        "follow_sight": false
      },
      "left_arm": {
        "pitch": -0.90,
        "yaw": 0.39,
        "roll": 0.0,
        "follow_sight": false
      }
    },
    "held_offhand": {
      "right_arm": {
        "pitch": -0.95,
        "yaw": -0.39,
        "roll": 0.0,
        "follow_sight": false
      },
      "left_arm": {
        "pitch": -0.90,
        "yaw": 0.39,
        "roll": 0.0,
        "follow_sight": false
      }
    }
  }
}

Each arm_properties section allows adjustment of arm positioning parameters. The "follow_sight" parameter enables arms to track the player's gaze direction, similar to how bows and crossbows function. When using custom axis configurations, the default model adjustment system is bypassed — it's recommended to configure both pitch and yaw values simultaneously for optimal results.