Answer by hoekkii

Personally I would go for a different approach, since the speed to angle conversion is not linear. But first of all some suggestions:
Try avoid duplicate code `PIN.transform.localEulerAngles = new Vector3(0f, 0f, Mathf.LerpAngle(PIN.transform.localEulerAngles.z, target200.z, Time.deltaTime));` can be converted to a method which will be: ///

/// Apply the angle in degrees to the pin ///

void ApplyAngle(float angle) { angle = Mathf.LerpAngle(PIN.transform.localEulerAngles.z, target200.z, Time.deltaTime); PIN.transform.localEulerAngles = new Vector3(0f, 0f, angle); } Also you have a if sequence of `if (velocityZ >= 0.1f && velocityZ <= 40)...` `if (velocityZ >= 40 && velocityZ <= 60)...`, when the velocityZ is exactly 40 it will pass both statements. instead you could do: `if (velocityZ > 180)...` `else if (velocityZ > 160)...`

But I recommended you to use a different approach, so here it is:

using UnityEngine; ///

/// Unfortunatly Unity does not expose interfaces ///

public abstract class MovableBehaviour : MonoBehaviour { ///

/// I don't know what this represents kilo Newton? ///

public float KN { get; protected set; } ///

/// Get the speed in meters per second ///

public float Speed { get; protected set; } }
using UnityEngine; [RequireComponent(typeof(Rigidbody))] public class Airplane : MovableBehaviour { [SerializeField] float _acceleration = 3.5f; Rigidbody _rigidbody; ///

/// Construct ///

void Awake() { _rigidbody = gameObject.GetComponent(); } ///

/// Initialize ///

void Start() { UpdateMovable(); } ///

/// Called at a fixed time step ///

void FixedUpdate() { // Add force var force = transform.forward; // Scale the force according to the user input and time step force *= GetInputForce() * Time.fixedDeltaTime; // Apply _rigidbody.AddForce(force); // Recalculate speed UpdateMovable(); } ///

/// Get the user applied force ///

float GetInputForce() { // Get input value var force = Input.GetAxis("Vertical"); // Apply stats force *= _acceleration; return force; } ///

/// Update the values for the interface ///

void UpdateMovable() { // Get speed var velocity = _rigidbody.velocity; var speed = velocity.magnitude; // Apply speed Speed = speed; // No idea what the meaning of this is const float knMultiplier = 1.943844f; KN = speed * knMultiplier; } }
using UnityEngine; ///

/// Unfortunatly Unity does not expose interfaces ///

public abstract class SpeedometerBehaviour : MonoBehaviour { ///

/// Converts speed to angle ///

public abstract float Speed2Angle(MovableBehaviour movable); }
using UnityEngine; public class Speedometer : SpeedometerBehaviour { public SpeedometerBehaviour Meter; public MovableBehaviour Movable; [SerializeField] Transform _indicator; [SerializeField] float _angleSmoothTime = 0.3f; float _angleVelocity; float _angle; ///

/// Constructor ///

void Awake() { // Set to negative infinity first to make sure angle is initialized correctly _angle = Mathf.NegativeInfinity; _angle = Meter.Speed2Angle(Movable); } ///

/// Called at the end of every frame ///

void LateUpdate() { // If meter is not assign, use default one (itself) if (Meter == null) Meter = this; // Get angle _angle = Meter.Speed2Angle(Movable); // Apply _indicator.localEulerAngles = new Vector3(0.0f, 0.0f, _angle); } /// public override float Speed2Angle(MovableBehaviour speed) { /* * Plot this data in a spreadsheet app * In this case I used Google Spreadsheets * Insert this data * 40 30 * 60 70 * 80 115 * 100 165 * 120 205 * 140 235 * 160 265 * 180 290 * 200 320 * * Select the data, click on insert chart * Select line chart * Go to the Customise tab, then Series * Toggle Trend line on. * Set the label to Use equation * Set the type to the one with the best result * In this case Polynomial. * * Now you see the required equation * */ // Apply the required equation var x = speed.KN; var y = -82.095f + 2.877f * x + -0.004f * x * x; // Clamp its value so it is safe y = Mathf.Clamp(y, 0.0f, 320.0f); // Fast up if (y > _angle) { _angleVelocity = 0.0f; return y; } // Smooth down return Mathf.SmoothDamp(_angle, y, ref _angleVelocity, _angleSmoothTime); } }
If you have any questions about the code, architecture or anything else, don't hesitate to ask them.