Default Value

The starting value of a variable or property when an instance spawns. Set in the Class Defaults panel.

Variable

A named storage slot for a value. Has a type (Boolean/Integer/Float/String/Vector/Object Reference/etc) and a default value.

Required input pin has no value wired to it

Why: The '{pin}' input on '{node}' must receive a value — either a wire from another node OR a default value in the pin field — but it's empty. Fix: Click on the '{pin}' input field on the '{node}' node. Either type a literal value (e.g. 5 for an integer), or drag a wire from another node's output. If you don't know what to connect, hover over the pin for a tooltip describing what it expects.

Select — choose value based on index or boolean

Pure node. Type-specific variants: SelectFloat, SelectInt, SelectVector, SelectObject, SelectString, SelectColor.

Clamp (float) — clamp float value between Min and Max

GetVariable and SetVariable pin naming rules

Variable node pin naming rules in UE5 Blueprints: - GetVariable: PURE node — NO exec pins. Single output pin named exactly after the variable (e.g. 'Health'). - SetVariable: exec in='execute', exec out='then'. Input pin named exactly after the variable (e.g. 'Health'). Output pin named exactly after the variable (returns new value). - Variable names ARE case-sensitive in connections. 'MyHealth' != 'myhealth'. - When connecting to SetVariable, the input pin name MUST match variable_name exactly.

SetScalarParameterValue — set a float parameter on a dynamic material

ParameterName must match the parameter name in the Material exactly (case-sensitive).

GetInputAxisValue — get current value of a named input axis (-1 to 1)

Legacy Input System. The axis name must match one defined in Project Settings → Input → Axis Mappings.

SetScalarParameterValue on dynamic material — change float material parameter

UMaterialInstanceDynamic method. Parameter name must match material graph.

Select (float) — choose between two floats based on bool condition

Pure node. bPickA=true returns A, bPickA=false returns B. Works for any type.