I have a planet and character. My player move perfect around planet with pressing key like 'w','s','a and 'D'. I want to move my player on every frame with same force around sphere. I try plane surface constant force code like this this.rigidbody.AddForce ( 3f,3f,3f);, when start playing game this code work fine but after some movement it stop my player on specific position of planet. I want to use this code for 3D sphere.

Any one can help me how can add constant force to my player on 3d sphere.?

I want add constant force to player when game start. I don't want any kind of planet's orbits, because my player is moving on all over the planet.

I try below link but it did not working for me. How can i accurately simulate orbits in unity.?

Here is my Sctipts


using UnityEngine;
using System.Collections;

public class PlayerController : MonoBehaviour {

public float moveSpeed = 10;
public Vector3 moveDir;
Rigidbody rigidbody;
// Update is called once per frame3

void Start(){
    rigidbody = GetComponent<Rigidbody> ();
void Update () {

    moveDir = new Vector3 (Input.GetAxisRaw("Horizontal")  ,0,Input.GetAxisRaw("Vertical"));
void FixedUpdate(){

    rigidbody.MovePosition (rigidbody.position + transform.TransformDirection(moveDir) * moveSpeed * Time.deltaTime);



using UnityEngine;
using System.Collections;

[RequireComponent (typeof (Rigidbody))]
public class FauxGravityBody : MonoBehaviour {

public FauxGravityAttractor attractor;
public Transform myTransform;
Rigidbody rigidbody;

// Use this for initialization++
void Awake(){

    this.rigidbody = GetComponent<Rigidbody> ();

void Start () {
    myTransform = transform;
    rigidbody.useGravity = false;
    rigidbody.constraints = RigidbodyConstraints.FreezeRotation;

// Update is called once per frame
void Update () {

    attractor.Attract (myTransform);


using UnityEngine;
using System.Collections;

public class FauxGravityAttractor : MonoBehaviour {

public float gravity = -10;
public void Attract(Transform body){

    Vector3 gravityUp = (body.position - transform.position).normalized;
    Vector3 bodyUp = body.up;

    body.GetComponent<Rigidbody>().AddForce (gravityUp * gravity);
    Quaternion targetRotation = Quaternion.FromToRotation (bodyUp, gravityUp) * body.rotation;
    body.rotation = Quaternion.Slerp (body.rotation, targetRotation, 50 * Time.deltaTime);

I am working with this scripts, If any one help me? then please.

  • 1
    \$\begingroup\$ Possible duplicate of How can I accurately simulate orbits in Unity? \$\endgroup\$ – Philipp Jun 9 '16 at 14:49
  • \$\begingroup\$ This is not duplicate. You put link for planet orbit. I don't want to move my player with orbit. My player is playing and jumping in all over the planet. @Philipp \$\endgroup\$ – mahesh Jun 9 '16 at 16:09
  • \$\begingroup\$ I want to apply constant force to my player with game start. By using your linked question script i can't do that. @Philipp \$\endgroup\$ – mahesh Jun 9 '16 at 16:16

There is the Faux gravity system in Unity and it works with jumping as well. TThis is the youtube link - https://m.youtube.com/watch?v=gHeQ8Hr92P4&fulldescription=1&client=mv-google&gl=ZW&hl=en. The download link for the unity project seems to be dead though. Ive uploaded the project to my mediafire account. I'l also add it to github when i get on a PC. link - http://www.mediafire.com/download/o7w7mogd6w3a4jc/Faux_Gravity_Example.7z

Edit 1: Adding constand force- In order to add a constant force to the player object, in the Player Controller script, edit the update method. Replace all the code in update with this

moveDirection = new Vector3(1,0,1);

I suggest you take a look at some basic C# tutorials before jumping into Unity. If this is for a school project or assignment, you wont learn much doing things this way. good luck.

| improve this answer | |
  • \$\begingroup\$ I see your tutorial and its not for unity 5. I change the scripts given in tutorial for unity 5, but still result is same. player not start moving around sphere with game start. I must have to press W,A,S and D key to move player. @zimspy \$\endgroup\$ – mahesh Jun 10 '16 at 7:32
  • \$\begingroup\$ I updated the scripts using Unity's Api updater before re-uploading them. \$\endgroup\$ – zimspy Jun 10 '16 at 12:31
  • \$\begingroup\$ Sorry for this, I forget this little thing. If I use Input.GetAxisRaw then i have to add value by pressing keys at runtim, and If i want to transform it directly with game start then I can specify value in Update() method and also I can set it at runtime by using variable. thanx for saving my time and brain. \$\endgroup\$ – mahesh Jun 10 '16 at 14:46

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