unreal_input_materials

The unreal_input_materials tool covers Enhanced Input setup and material instance management. It exposes 6 operations for creating input actions, building mapping contexts, adding key bindings, and creating and configuring material instances.

Operations at a Glance

Operation	Hint	Description
`create_input_action`	—	Create an Enhanced Input action asset
`create_mapping_context`	—	Create an Input Mapping Context asset
`add_mapping`	—	Add an action mapping to a context with key bindings
`create_material_instance`	—	Create a Material Instance from a parent material
`set_material_parameters`	idempotent	Set scalar, vector, and texture parameters on an instance
`get_material_info`	readOnly	Get all parameters and their current values from a material

create_input_action

Creates a new Enhanced Input UInputAction asset. Input Actions define what player actions exist (Jump, Attack, Move) independently of which keys trigger them.

Parameters

Parameter	Type	Required	Description
`path`	string	yes	Destination content path including asset name
`value_type`	string	yes	Action value type: `bool`, `axis1d`, `axis2d`, `axis3d`
`triggers`	array	no	Default trigger types to add: `pressed`, `released`, `held`, `tap`, `double_tap`
`modifiers`	array	no	Default modifier types: `negate`, `swizzle`, `dead_zone`, `scalar`

{
  "operation": "create_input_action",
  "params": {
    "path": "/Game/Input/Actions/IA_Jump",
    "value_type": "bool",
    "triggers": ["pressed"]
  }
}

{
  "operation": "create_input_action",
  "params": {
    "path": "/Game/Input/Actions/IA_Move",
    "value_type": "axis2d"
  }
}

{
  "operation": "create_input_action",
  "params": {
    "path": "/Game/Input/Actions/IA_Look",
    "value_type": "axis2d",
    "modifiers": ["dead_zone"]
  }
}

Response

{
  "path": "/Game/Input/Actions/IA_Jump",
  "value_type": "bool",
  "created": true
}

Note: Input Actions define the semantic intent of player input — not the physical key. Physical key bindings are added separately via add_mapping on a Mapping Context.

create_mapping_context

Creates a new UInputMappingContext asset. Mapping Contexts group a set of action-to-key bindings that can be activated and deactivated together at runtime.

Parameters

Parameter	Type	Required	Description
`path`	string	yes	Destination content path including asset name
`priority`	integer	no	Default priority when added to the player. Higher values take precedence. Default: 0.

{
  "operation": "create_mapping_context",
  "params": {
    "path": "/Game/Input/IMC_Default",
    "priority": 0
  }
}

{
  "operation": "create_mapping_context",
  "params": {
    "path": "/Game/Input/IMC_UI",
    "priority": 10
  }
}

Response

{
  "path": "/Game/Input/IMC_Default",
  "priority": 0,
  "created": true
}

add_mapping

Adds an action-to-key binding to an existing Mapping Context. Each call adds one mapping entry.

Parameters

Parameter	Type	Required	Description
`context`	string	yes	Full content path of the Mapping Context
`action`	string	yes	Full content path of the Input Action
`key`	string	yes	Key identifier string (see key names below)
`modifiers`	array	no	Modifiers to apply to this mapping: `negate`, `swizzle`, `dead_zone`, `scalar`
`triggers`	array	no	Triggers for this specific mapping: `pressed`, `released`, `held`

Common Key Names

Key String	Physical Key
`SpaceBar`	Space
`LeftMouseButton`	Left click
`RightMouseButton`	Right click
`W`, `A`, `S`, `D`	WASD
`Gamepad_FaceButton_Bottom`	Xbox A / PS Cross
`Gamepad_FaceButton_Right`	Xbox B / PS Circle
`Gamepad_LeftX`	Left stick horizontal axis
`Gamepad_LeftY`	Left stick vertical axis
`Gamepad_RightX`	Right stick horizontal axis
`Gamepad_RightY`	Right stick vertical axis
`Gamepad_LeftTriggerAxis`	Left trigger
`Gamepad_RightTriggerAxis`	Right trigger
`Gamepad_LeftShoulder`	LB / L1
`Gamepad_RightShoulder`	RB / R1

{
  "operation": "add_mapping",
  "params": {
    "context": "/Game/Input/IMC_Default",
    "action": "/Game/Input/Actions/IA_Jump",
    "key": "SpaceBar"
  }
}

{
  "operation": "add_mapping",
  "params": {
    "context": "/Game/Input/IMC_Default",
    "action": "/Game/Input/Actions/IA_Jump",
    "key": "Gamepad_FaceButton_Bottom"
  }
}

{
  "operation": "add_mapping",
  "params": {
    "context": "/Game/Input/IMC_Default",
    "action": "/Game/Input/Actions/IA_Move",
    "key": "Gamepad_LeftY",
    "modifiers": ["dead_zone"]
  }
}

Tip: Call add_mapping once per key binding. To add both keyboard and gamepad bindings for the same action, call it twice with different key values — both mappings live in the same context.

create_material_instance

Creates a new UMaterialInstance asset derived from a parent material. Material instances let you vary parameters (colors, textures, scalars) without creating a new material shader.

Parameters

Parameter	Type	Required	Description
`path`	string	yes	Destination content path including asset name
`parent`	string	yes	Full content path of the parent material

{
  "operation": "create_material_instance",
  "params": {
    "path": "/Game/Materials/MI_Rock_Mossy",
    "parent": "/Game/Materials/M_Rock_Base"
  }
}

{
  "operation": "create_material_instance",
  "params": {
    "path": "/Game/Characters/Enemies/MI_Goblin_Green",
    "parent": "/Game/Characters/Enemies/M_Goblin_Base"
  }
}

Response

{
  "path": "/Game/Materials/MI_Rock_Mossy",
  "parent": "/Game/Materials/M_Rock_Base",
  "created": true
}

set_material_parameters

Sets scalar, vector, and texture parameters on a material instance. Only overrides the parameters you specify — all others inherit from the parent.

Parameters

Parameter	Type	Required	Description
`path`	string	yes	Full content path of the material instance
`scalars`	object	no	Map of scalar parameter names to float values
`vectors`	object	no	Map of vector parameter names to `{ r, g, b, a }` objects
`textures`	object	no	Map of texture parameter names to full content paths

{
  "operation": "set_material_parameters",
  "params": {
    "path": "/Game/Materials/MI_Rock_Mossy",
    "scalars": {
      "Roughness": 0.8,
      "Metallic": 0.0,
      "MossAmount": 0.6
    },
    "vectors": {
      "BaseColor": { "r": 0.18, "g": 0.28, "b": 0.14, "a": 1.0 }
    },
    "textures": {
      "DiffuseTexture": "/Game/Textures/T_Rock_Mossy_D",
      "NormalMap":      "/Game/Textures/T_Rock_Mossy_N"
    }
  }
}

{
  "operation": "set_material_parameters",
  "params": {
    "path": "/Game/Characters/Enemies/MI_Goblin_Green",
    "scalars": {
      "EmissiveStrength": 0.0
    },
    "vectors": {
      "SkinTint": { "r": 0.22, "g": 0.45, "b": 0.12, "a": 1.0 }
    }
  }
}

Note: set_material_parameters is tagged idempotentHint. Applying the same parameters twice produces the same result. Safe to parallelize across different material instance paths.

get_material_info

Returns all parameters defined in a material or material instance, along with their current values and whether they are overriding the parent.

Parameters

Parameter	Type	Required	Description
`path`	string	yes	Full content path of the material or material instance

{
  "operation": "get_material_info",
  "params": {
    "path": "/Game/Materials/MI_Rock_Mossy"
  }
}

Response

{
  "name": "MI_Rock_Mossy",
  "parent": "/Game/Materials/M_Rock_Base",
  "scalars": [
    { "name": "Roughness",   "value": 0.8,  "overriding": true  },
    { "name": "Metallic",    "value": 0.0,  "overriding": true  },
    { "name": "MossAmount",  "value": 0.6,  "overriding": true  },
    { "name": "Opacity",     "value": 1.0,  "overriding": false }
  ],
  "vectors": [
    { "name": "BaseColor", "value": { "r": 0.18, "g": 0.28, "b": 0.14, "a": 1.0 }, "overriding": true }
  ],
  "textures": [
    { "name": "DiffuseTexture", "value": "/Game/Textures/T_Rock_Mossy_D", "overriding": true  },
    { "name": "NormalMap",      "value": "/Game/Textures/T_Rock_Mossy_N", "overriding": true  },
    { "name": "RoughnessMap",   "value": "/Game/Textures/T_Rock_Rough",   "overriding": false }
  ]
}

Note: get_material_info is tagged readOnlyHint — safe to parallelize with other read-only calls.

Complete Workflow: Enhanced Input Setup

// 1. Create input actions (can parallelize — independent assets)
await parallel([
  create_input_action({ path: "/Game/Input/Actions/IA_Jump",   value_type: "bool",   triggers: ["pressed"] }),
  create_input_action({ path: "/Game/Input/Actions/IA_Move",   value_type: "axis2d" }),
  create_input_action({ path: "/Game/Input/Actions/IA_Look",   value_type: "axis2d", modifiers: ["dead_zone"] }),
  create_input_action({ path: "/Game/Input/Actions/IA_Attack", value_type: "bool",   triggers: ["pressed"] }),
])

// 2. Create the mapping context
await create_mapping_context({ path: "/Game/Input/IMC_Default", priority: 0 })

// 3. Add keyboard mappings
await add_mapping({ context: "/Game/Input/IMC_Default", action: "/Game/Input/Actions/IA_Jump",   key: "SpaceBar" })
await add_mapping({ context: "/Game/Input/IMC_Default", action: "/Game/Input/Actions/IA_Attack", key: "LeftMouseButton" })

// Move uses 4 keys (WASD) — add each separately
await add_mapping({ context: "/Game/Input/IMC_Default", action: "/Game/Input/Actions/IA_Move", key: "W", modifiers: [] })
await add_mapping({ context: "/Game/Input/IMC_Default", action: "/Game/Input/Actions/IA_Move", key: "S", modifiers: ["negate"] })
await add_mapping({ context: "/Game/Input/IMC_Default", action: "/Game/Input/Actions/IA_Move", key: "D", modifiers: ["swizzle"] })
await add_mapping({ context: "/Game/Input/IMC_Default", action: "/Game/Input/Actions/IA_Move", key: "A", modifiers: ["swizzle", "negate"] })

// 4. Add gamepad mappings
await add_mapping({ context: "/Game/Input/IMC_Default", action: "/Game/Input/Actions/IA_Jump",   key: "Gamepad_FaceButton_Bottom" })
await add_mapping({ context: "/Game/Input/IMC_Default", action: "/Game/Input/Actions/IA_Attack", key: "Gamepad_RightTriggerAxis" })
await add_mapping({ context: "/Game/Input/IMC_Default", action: "/Game/Input/Actions/IA_Move",   key: "Gamepad_LeftY" })
await add_mapping({ context: "/Game/Input/IMC_Default", action: "/Game/Input/Actions/IA_Move",   key: "Gamepad_LeftX", modifiers: ["swizzle"] })
await add_mapping({ context: "/Game/Input/IMC_Default", action: "/Game/Input/Actions/IA_Look",   key: "Gamepad_RightX" })
await add_mapping({ context: "/Game/Input/IMC_Default", action: "/Game/Input/Actions/IA_Look",   key: "Gamepad_RightY", modifiers: ["negate"] })

Complete Workflow: Material Variant Set

// 1. Get the parent material's parameter list
const info = await get_material_info({ path: "/Game/Materials/M_Rock_Base" })

// 2. Create multiple instance variants (parallelize — different paths)
await parallel([
  create_material_instance({ path: "/Game/Materials/MI_Rock_Mossy", parent: "/Game/Materials/M_Rock_Base" }),
  create_material_instance({ path: "/Game/Materials/MI_Rock_Dry",   parent: "/Game/Materials/M_Rock_Base" }),
  create_material_instance({ path: "/Game/Materials/MI_Rock_Snow",  parent: "/Game/Materials/M_Rock_Base" }),
])

// 3. Set parameters on each variant (parallelize — different paths)
await parallel([
  set_material_parameters({
    path: "/Game/Materials/MI_Rock_Mossy",
    scalars: { Roughness: 0.8, MossAmount: 0.7 },
    vectors: { BaseColor: { r: 0.18, g: 0.28, b: 0.14, a: 1.0 } },
    textures: { DiffuseTexture: "/Game/Textures/T_Rock_Mossy_D" }
  }),
  set_material_parameters({
    path: "/Game/Materials/MI_Rock_Dry",
    scalars: { Roughness: 0.95, MossAmount: 0.0 },
    vectors: { BaseColor: { r: 0.42, g: 0.38, b: 0.30, a: 1.0 } },
    textures: { DiffuseTexture: "/Game/Textures/T_Rock_Dry_D" }
  }),
  set_material_parameters({
    path: "/Game/Materials/MI_Rock_Snow",
    scalars: { Roughness: 0.6, MossAmount: 0.0, SnowAmount: 0.9 },
    vectors: { BaseColor: { r: 0.9, g: 0.92, b: 0.95, a: 1.0 } },
    textures: { DiffuseTexture: "/Game/Textures/T_Rock_Snow_D" }
  }),
])