Processors

An input processor takes a value and returns a processed version of it. The received value and result value must be of the same type. For example, you can use a Clamp processor to clamp values from a control to a certain range.

NOTE: To convert received input values into different types, see composite bindings.

• Using Processors
  • Processors on Bindings
  • Processors on Actions
  • Processors on Controls
• Predefined Processors
  • Axis Deadzone
  • Clamp
  • Invert
  • Invert Vector 2
  • Invert Vector 3
  • Normalize
  • Normalize Vector 2
  • Normalize Vector 3
  • Scale
  • Scale Vector 2
  • Scale Vector 3
  • Stick Deadzone
• Writing Custom Processors

Using Processors

Processors can be installed on bindings, actions or on controls.

Processors on Bindings

When you create bindings for your actions, you can choose to add processors to the bindings to process the values read from the controls they bind to, before applying them to the action value. For instance you may find that you want the Vector2 values coming from the controls to be inverted along the Y axis before passing these values to your action driving your game input logic. You can achieve this by adding an Invert Vector2 processor to your binding.

If you are using Input Action Assets, you can simply add any processor to your bindings in the input action editor. Once you created some bindings, just select the binding you want to add processors to (so that the right pane of the window shows the properties for that binding). Now, click on the "Plus" icon on the "Processors" foldout, which will show a popup of all available processors matching your control type. Choose a processor type to add a processor instance of that type. The processor will now be shown under the processors foldout. If the processor has any parameters you can now edit them here as well:

You can click the "Minus" button next to a processor to remove it. You can click the "up" and "down" arrows to change the order of processors (which affect in which order values are being processed).

If you create your bindings in code, you can add processors like this:

var action = new InputAction();
action.AddBinding("<Gamepad>/leftStick")
    .WithProcessor("invertVector2(invertX=false)");

Processors on Actions

Processors on actions work very similar to processors on bindings, but they affect all controls bound to an action, not just the ones coming from a specific binding. If there are processors on both the binding and the action, the ones from the binding will be processed first.

You can add and edit processors on actions in the Input Action Assets the same way as you would do for bindings - just add them in the right window pane when you have selected an action to edit.

If you create your actions in code, you can add processors like this:

var action = new InputAction(processors: "invertVector2(invertX=false)");

Processors on Controls

You can also have any number processors directly on an InputControl, which then process the values read from the control. Whenever you call ReadValue on a control, any processor of the control will process the value before it gets returned to you. You can use ReadUnprocessedValue on a control to bypass the processors.

Processors get added to a control during device creation, if they are specified in the control's layout (You cannot add processors to existing controls after they have been created). So adding processors to controls is something you'd only be doing when you are creating custom devices. The devices supported by the input system out of the box already have processors added on controls, where it is useful - for instance sticks on gamepads will always have a Stick Deadzone Processor.

If you are using a layout generated by the input system from a state struct using InputControlAttributes, you can specify the processors to use using the processors property of the attribute like this:

public struct MyDeviceState : IInputStateTypeInfo
{
    public FourCC format => return new FourCC('M', 'Y', 'D', 'V');

    // Add an axis deadzone to the control to ignore values
    // smaller then 0.2, as our control does not have a stable
    // resting position.
    [InputControl(layout = "Axis", processors = "AxisDeadzone(min=0.2)")]
    public short axis;
}

If you create a layout from JSON, you can specify processors on your controls like this:

{
    "name" : "MyDevice",
    "extend" : "Gamepad", // Or some other thing
    "controls" : [
        {
            "name" : "axis",
            "layout" : "Axis",
            "offset" : 4,
            "format" : "FLT",
            "processors" : "AxisDeadzone(min=0.2)"
        }
    ]
}

Predefined Processors

The input system package comes with a set of useful processors you can use.

Axis Deadzone

Name	AxisDeadzone
Operand Type	float
Parameters	float min float max

An Axis Deadzone Processor scales the values of a control, so that any value with an absolute value smaller than min is 0, and any value with an absolute value larger than max is 1 or -1. Many controls don't have an imprecise resting point (ie, they don't always report exactly 0 when the control is in the center). Using a the min value on a deadzone processor avoids unintentional input from such controls. Also, some controls don't consistently report they maximum values when moving the axis all the way. Using a the max value on a deadzone processor can make sure that you always get the maximum value in such cases.

Clamp

Name	Clamp
Operand Type	float
Parameters	float min float max

Clamps input values to the [min..max] range.

Invert

Name	Invert
Operand Type	float

Inverts (ie, multiply by -1) the values from a control.

Invert Vector 2

Name	InvertVector2
Operand Type	Vector2
Parameters	bool invertX bool invertY

Inverts (ie, multiply by -1) the values from a control. Will invert the x axis of the vector if invertX is true, and the y axis if invertY is true.

Invert Vector 3

Name	InvertVector3
Operand Type	Vector3
Parameters	bool invertX bool invertY bool invertZ

Inverts (ie, multiply by -1) the values from a control. Will invert the x axis of the vector if invertX is true, the y axis if invertY is true, and the z axis if invertZ is true.

Normalize

Name	Normalize
Operand Type	float
Parameters	float min float max float zero

Normalizes input values in the range [min..max] to unsigned normalized form [0..1] if min is >= zero and to signed normalized form [-1..1] if min < zero.

Normalize Vector 2

Name	NormalizeVector2
Operand Type	Vector2

Normalizes input vectors to be of unit length (1). This is the same as calling Vector2.normalized.

Normalize Vector 3

Name	NormalizeVector3
Operand Type	Vector3

Normalizes input vectors to be of unit length (1). This is the same as calling Vector3.normalized.

Scale

Name	Scale
Operand Type	float
Parameters	float factor

Multiply all input values by factor.

Scale Vector 2

Name	ScaleVector2
Operand Type	Vector2
Parameters	float x float y

Multiply all input values by x along the x axis and by y along the y axis.

Scale Vector 3

Name	ScaleVector3
Operand Type	Vector3
Parameters	float x float y float x

Multiply all input values by x along the x axis, by y along the y axis and by z along the z axis.

Stick Deadzone

Name	StickDeadzone
Operand Type	Vector2
Parameters	float min float max

A Stick Deadzone Processor scales the values of a Vector2 control (such as a stick), so that input vector with a magnitude smaller than min results in (0,0), and any input vector with a magnitude larger than max is normalized to length 1. Many controls don't have an imprecise resting point (ie, they don't always report exactly 0 when the control is in the center). Using a the min value on a deadzone processor avoids unintentional input from such controls. Also, some controls don't consistently report they maximum values when moving the axis all the way. Using a the max value on a deadzone processor can make sure that you always get the maximum value in such cases.

Writing Custom Processors

You can also write a custom processor to use in your project. Newly added processors are usable in the UI and data the same way that built-in processors are. Simply add a class deriving from InputProcessor<TValue>, and implement the Process method:

public class MyValueShiftProcessor : InputProcessor<float>
{
    [Tooltip("Number to add to incoming values.")]
    public float valueShift = 0;

    public override float Process(float value, InputControl<float> control)
    {
        return value + valueShift;
    }
}

Now, you need to tell the Input System about your processor. So, somewhere in your initialization code, you should call:

InputSystem.RegisterProcessor<MyValueShiftProcessor>();

Now, your new processor will become available up in the Input Action Asset Editor window, and you can also add it in code like this:

var action = new InputAction(processors: "myvalueshift(valueShift=2.3)");