Version: 2021.2
LanguageEnglish
  • C#

ForceMode2D

enumeration

Suggest a change

Success!

Thank you for helping us improve the quality of Unity Documentation. Although we cannot accept all submissions, we do read each suggested change from our users and will make updates where applicable.

Close

Submission failed

For some reason your suggested change could not be submitted. Please <a>try again</a> in a few minutes. And thank you for taking the time to help us improve the quality of Unity Documentation.

Close

Cancel

Description

Option for how to apply a force using Rigidbody2D.AddForce.

Use this to apply a certain type of force to a 2D RigidBody. There are two types of forces to apply: Force mode and Impulse Mode. For a 3D Rigidbody see ForceMode.

//This script adds force to a Rigidbody. The kind of force is determined by which buttons you click.

//Create a Sprite and attach a Rigidbody2D component to it //Attach this script to the Sprite

using UnityEngine; using UnityEngine.EventSystems;

public class AddingForce : MonoBehaviour { //Use to switch between Force Modes enum ModeSwitching { Start, Impulse, Force }; ModeSwitching m_ModeSwitching;

//Use this to change the different kinds of force ForceMode2D m_ForceMode; //Start position of the RigidBody, use to reset Vector2 m_StartPosition;

//Use to apply force to RigidBody Vector2 m_NewForce;

//Use to manipulate the RigidBody of a GameObject Rigidbody2D m_Rigidbody;

void Start() { //Fetch the RigidBody component attached to the GameObject m_Rigidbody = GetComponent<Rigidbody2D>(); //Start at first mode (nothing happening yet) m_ModeSwitching = ModeSwitching.Start;

//Initialising the force to use on the RigidBody in various ways m_NewForce = new Vector2(-5.0f, 1.0f);

//This is the RigidBody's starting position m_StartPosition = m_Rigidbody.transform.position; }

void Update() { //Switching modes depending on button presses switch (m_ModeSwitching) { //This is the starting mode which resets the GameObject case ModeSwitching.Start:

//Reset to starting position of RigidBody m_Rigidbody.transform.position = m_StartPosition; //Reset the velocity of the RigidBody m_Rigidbody.velocity = new Vector2(0f, 0f); break;

//This is the Force Mode case ModeSwitching.Force: //Make the GameObject travel upwards m_NewForce = new Vector2(0, 1.0f); //Use Force mode as force on the RigidBody m_Rigidbody.AddForce(m_NewForce, ForceMode2D.Force); break;

//This is the Impulse Mode case ModeSwitching.Impulse: //Make the GameObject travel upwards m_NewForce = new Vector2(0f, 1.0f); //Use Impulse mode as a force on the RigidBody m_Rigidbody.AddForce(m_NewForce, ForceMode2D.Impulse); break; } }

//These are the Buttons for telling what Force to apply as well as resetting void OnGUI() { //If reset button pressed if (GUI.Button(new Rect(100, 0, 150, 30), "Reset")) { //Switch to start/reset case

m_ModeSwitching = ModeSwitching.Start; }

//Impulse button pressed if (GUI.Button(new Rect(100, 60, 150, 30), "Apply Impulse")) { //Switch to Impulse mode (apply impulse forces to GameObject)

m_ModeSwitching = ModeSwitching.Impulse; }

//Force Button Pressed if (GUI.Button(new Rect(100, 90, 150, 30), "Apply Force")) { //Switch to Force mode (apply force to GameObject) m_ModeSwitching = ModeSwitching.Force; } } }

Properties

ForceAdd a force to the Rigidbody2D, using its mass.
ImpulseAdd an instant force impulse to the rigidbody2D, using its mass.