How to use the ConstantForce component?

Questions & Answers
1

I am having trouble with this error.

Assets/Underwater.js(46,47): BCE0020: An instance of type ‘UnityEngine.ConstantForce’ is required to access non static member ‘relativeForce’.
Which is on this line.

ConstantForce.relativeForce = new Vector3(0, -200, 0);

I am totally confused.

#pragma strict


public var waterLevel : float;
private var isUnderwater : boolean;
private var normalColor : Color;
private var underwaterColor : Color;
private var swimDirection = Vector3.zero;
private var chMotor : PlayerMovement;
private var chMotorscript : CharacterMotor;
public var relativeForce: Vector3;

//public var scriptName : GameObject;
//public var Player : Transform;


function Start () {
		normalColor = new Color (0.5f, 0.5f, 0.5f, 0.5f);
		underwaterColor = new Color (0.3f, 0.4f, 0.43f, 9f);
		chMotor = GetComponent(PlayerMovement);
		chMotorscript = GetComponent(CharacterMotor);
		

	
}

function Update () {
if((transform.position.y < waterLevel) != isUnderwater);
			{
				isUnderwater = transform.position.y < waterLevel;
				if (isUnderwater) SetUnderwater ();
				if (!isUnderwater) SetNormal();
			}
			
			if(isUnderwater && Input.GetKey(KeyCode.E))
			{
				ConstantForce.relativeForce = new Vector3(0, -200, 0);
			}
			else
			{
				ConstantForce.relativeForce = new Vector3(0, 0, 0);

			}
			if(isUnderwater && Input.GetKey(KeyCode.Q))
			{
				ConstantForce.relativeForce = new Vector3(0, 200, 0);

			}

		}
			
function SetNormal()
	{
		RenderSettings.fogColor = normalColor;
		RenderSettings.fogDensity = 0.002f;
		RenderSettings.fogEndDistance = 500;

	}
	
function SetUnderwater()
	{
		RenderSettings.fogColor = underwaterColor;
		RenderSettings.fogDensity = 0.04f;
		RenderSettings.fogEndDistance = 20;
		Debug.Log("hi");
		chMotor.walkSpeed = 2;
		chMotor.runSpeed = 3;
		chMotor.enableCrouch = false;
		chMotor.gravity = 5;
		chMotor.enableFallingDamage = false;
		//chMotor.slideWhenOverSlopeLimit = false;

		
		
		
		
	}
2

As an error says - you need an instance of ConstantForce. Add ConstantForce component to your object either via Inspector or script. And then:

//You can use GetComponent
private ConstantForce waterForce;
private void Awake()
{
    waterForce = GetComponent<ConstantForce>();
}
//or
public ConstantForce waterForce; //and assign it in Inspector
//or
[SerializeField]
private ConstantForce waterForce; //and assign in Inspector
//or provide it from another script

//then use it like:
waterForce.relativeForce = new Vector3();//your vector