I made a car controller in unity to drive around. I've read FixedUpdate is better to use for physical objects instead of Update, but when I switch to Fixed update my car no longer drives. Does anyone know why this might be? Thank so much you for any help you an provide!
public float speed;
public float turnSpeed;
private RigidBody rb;
void Start()
{
rb = GetComponent<Rigidbody>();
}
// Update is called once per frame
void FixedUpdate()
{
Move();
Turn();
}
void Move(){
// moves the car
if (Input.GetKey(KeyCode.W)){
rb.AddRelativeForce(new Vector3(Vector3.forward.x, 0, Vector3.forward.z) * speed);
}
else if (Input.GetKey(KeyCode.S)){
rb.AddRelativeForce(new Vector3(Vector3.forward.x, 0, Vector3.forward.z) * -speed);
}
// maintains forward velocity relative to car.
Vector3 localVelocity = transform.InverseTransformDirection(rb.velocity);
localVelocity.x = 0;
rb.velocity = transform.TransformDirection(localVelocity);
}
void Turn(){
// turns the car.
if (Input.GetKey(KeyCode.D)){
rb.AddRelativeTorque(Vector3.up * turnSpeed);
Debug.Log("TURNING CAR");
}
else if (Input.GetKey(KeyCode.A)){
rb.AddRelativeTorque(-Vector3.up * turnSpeed);
Debug.Log("TURNING CAR");
}
Here's the code. Pressing W or S adds a force, pressing A or D adds a torque. When I try turning in FixedUpdate the console will write "TURNING CAR" as it should which shows that it's making past the AddRelativeTorque line, but it still won't turn so I'm not really sure what's going on. Thanks again, I really appreciate any help.
Try increasing the force used.
Fixed update runs less frequently than update (using the default settings, in most scenarios). Since the code is running much less frequently, less force is being accumulated over the same time period.
Consider a game running at 100fps. The default fixed time step is 0.02s (50 frames per second). Since update is running at 100fps, you have twice as much force being applied from update than would be applied from fixed update.
If you make your force value independent of the time since the last update happened, you will not need to worry about this.
For Update use myForceValue * Time.deltaTime.
For FixedUpdate use myForceValue * Time.fixedDeltaTime.
Related
So I am trying to make a multiplayer game with abilities sort of like Overwatch/Paladins. All in all, one ability should be a sort of projectile that moves across the ground and allows that player to teleport to its position at any time while it is alive. I can't find the solution to teleporting only the player that shot it since thus far in my tests, when one player activated their ability, all players would teleport. How can I solve this?
My code:
void Update()
{
if (Input.GetKeyDown(KeyCode.E))
GetComponent<playerController>().heldAbility = "gateCrash";
if (GetComponent<playerController>().heldAbility == "gateCrash")
holding = true;
else
holding = false;
if (holding && Input.GetMouseButtonDown(0))
PhotonNetwork.Instantiate(Path.Combine("PhotonPrefabs", "GateCrashModel"), spawnPos, transform.rotation, 0);
}
This code is attached to the projectile:
public float speed = 10;
PhotonView pv;
private void Awake()
{
pv = transform.GetComponent<PhotonView>();
}
private void FixedUpdate()
{
transform.Translate(transform.forward * speed * Time.fixedDeltaTime);
}
I guess that I should make have something as instatntiation parameter but idk what.
A simple approach would be to add a shotOwner property to each of your projectiles. Every time a projectile is fired, update shotOwner to point to the player object that fired the shot. (This will also let you implement "Player_X killed Player_Y" functionality, among other things.)
I want to make sure that various objects moving at high speed cannot pass through walls or other objects. My thought process was to check via Raycast if a collision has occurred between two moments of movement.
So the script should remember the previous position and check via Raycast for collisions between previous and current position.
If a collision has occurred, the object should be positioned at the meeting point and moved slightly in the direction of the previous position.
My problem is that works outside the map not inside. If I go from inside to outside, I can go through the walls. From outside to inside not.
Obviously I have misunderstood something regarding the application with raycasts.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class ObsticalControll : MonoBehaviour
{
private Vector3 positionBefore;
public LayerMask collisionLayer = 9;
private Vector3 lastHit = new Vector3(0, 0, -20);
// Start is called before the first frame update
void Start()
{
positionBefore = transform.position;
}
private void OnDrawGizmos()
{
Gizmos.DrawCube(lastHit, new Vector3(.2f,.2f,.2f));
}
// Update is called once per frame
void Update()
{
Vector3 curruentMovement = transform.position;
Vector2 dVector = (Vector2)transform.position - (Vector2)positionBefore;
float distance = Vector2.Distance((Vector2)positionBefore, (Vector2)curruentMovement);
RaycastHit2D[] hits = Physics2D.RaycastAll((Vector2)positionBefore, dVector, distance, collisionLayer);
if(hits.Length > 0)
{
Debug.Log(hits.Length);
for (int i = hits.Length -1 ; i >= 0 ; i--)
{
RaycastHit2D hit = hits[i];
if (hit.collider != null)
{
Debug.Log("hit");
lastHit.x = hit.point.x;
lastHit.y = hit.point.y;
Vector3 resetPos = new Vector3(hit.point.x, hit.point.y, transform.position.z) + positionBefore.normalized * 0.1f;
transform.position = new Vector3(resetPos.x, resetPos.y, transform.position.z);
}
}
}
positionBefore = transform.position;
}
}
Theres a better way to deal with this that unity has built in.
Assuming the object thats moving at a high speed has a RigidBody(2d in your case) you can set its Collision Detection to Continuous instead of Discrete.
This will help collisions with high speed collision, assuming that its moving at high speed and the wall is not moving.
If for some reason you cannot apply this to your scenario, Ill try to help with the raycast solution.
However, I am still wondering about the collision behavior of my raycast script. That would be surely interesting, if you want to calculate shots or similar via raycast
Alright, so your initial idea was to check if a collision had occurred, By checking its current position and its previous position. And checking if anything is between them, that means a collision has occurred. And you would teleport it back to where it was suppose to have hit.
A better way todo this would be to check where the GameObject would be in the next frame, by raycasting ahead of it, by the distance that it will travel. If it does hit something that means that within the next frame, it would have collided with it. So you could stop it at the collision hit point, and get what it has hit. (This means you wouldn't have to teleport it back, So there wouldn't be a frame where it goes through then goes back)
Almost the same idea but slightly less complicated.
Problem would be that if another object were to appear between them within the next frame aswell, it could not account for that. Which is where the rigidbody.movePosition shines, And with OnCollisionEnter you can detect when and what it collided with correctly. Aswell as without the need to teleport it back
I am new to unity and I am creating my first ever endless runner game. I currently have a cube as a player and another cube (prefab) as the track. I have created a script which aims at instantiating the prefab at runtime and moving the track towards the player (instead of moving the player). For some reason, the tracks instantiated at runtime are being generated at the same position and don't seem to move towards the player. Could anyone tell me if I am doing it right please? How do I generate an infinite/endless track? Thanks in advance
public GameObject[] trackPieces;
public float trackLength;
public float trackSpeed;
private GameObject trackObject;
// Update is called once per frame
void Update ()
{
GenerateInfiniteTrack();
}
private void GenerateInfiniteTrack()
{
trackObject = InstantiatePrefab();
trackObject.transform.Translate(-Vector3.forward * Time.deltaTime * trackSpeed);
}
private GameObject InstantiatePrefab()
{
return Instantiate(trackPieces[Random.Range(0, trackPieces.Length)]) as GameObject;
}
trackObject is overwritten every frame
Your track is not moving because the call to move it occurs only once at instantiation and never again. The value of which track to move is overwritten every update(). Here is what happens:
Every update you make a call to:
private void GenerateInfiniteTrack()
When this method is called you instantiate a new prefab (new instance of your object) and tell the object to move via
trackObject.transform.Translate(-Vector3.forward * Time.deltaTime * trackSpeed);
When you call the method the next time you lose the reference to the original object because you are creating another one that replaces the value held in trackObject. So the previously generated object will never move again. Your new object moves once and then is lost, again, and repeat.
Below I have suggested some code that may work. You will still have to decide how you will dispose of the track objects since you are creating them at a very fast rate. If you can think of a way to use InvokeRepeating() to address this problem, then that would be the cleanest. Invoke repeating has some limitations, like not being able to pass parameters to your repeating function so I did not use it here, but it is conceivably an alternative.
Here is my example.
var TrackObjects = new List<GameObject>();
private void MoveInfiniteTrack()
{
foreach(GameObject gO in TrackObjects )
{
gO.transform.Translate(-Vector3.forward * Time.deltaTime * trackSpeed);
}
}
private void GenerateInfiniteTrack()
{
TrackObject = InstantiatePrefab();
TrackObjects.Add(TrackObject);
}
void Update ()
{
GenerateInfiniteTrack();
MoveInfiniteTrack()
}
void Foo()
{
// Delete your track on some kind schedule or you will quickly get infinite objects and massive lag.
}
As a general observation, creating track this much (60x a second) is very inefficient. I would suggest that you either:
A. Create much larger segments of track, for example once every 1 or 10 seconds and move it along. I don't remember exactly how to do this, but it went something like this:
var lastchecked= datetime.now
Update()
{
if((datetime.now - lastchecked).seconds > 1)
{
// put here what you will do every 1 second.
lastchecked= datetime.now
}
}
B. Create a large cylinder and rotate it to use as a track.
I'm making 2D mobile game and I have a ball, but my ball doesn't have a constant moving speed. What I need to do?
When I build game on my android device, ball have a various speed. In that case, my game is not playable.
I hope that someone can help me. Thanks.
This is on my start function:
void Start () {
GetComponent<Rigidbody2D> ()
.AddForce (new Vector2 (1f, 0.5f)* Time.deltaTime * force);
}
Is it a good practice if I used in code " Application.LoadLevel ("__Scena_0"); " to load existing scene when I lose " life" ? Problem happens when I lost " life " and try playing game in second chance.
My update function is about OnTriggerEnter2D when my ball hit trigger objects.
EDIT 23.12.2015. : problem solve with adding physics material (fiction 0) and adding to script:
using UnityEngine.SceneManagement;
...
SceneManager.LoadScene ("MainScene");
The problem is the calculation of the force vector:
new Vector2 (1f, 0.5f) * Time.deltaTime * force
You are using Time.deltaTime as a factor, which means that the applied force is not constant, but depending on the deltaTime, which is the duration of the last frame. This explains why it changes randomly.
I don't think Time.deltaTime is what you want here, try just removing the factor and adjusting the "force" factor accordingly. You should now have a constant force applied, independent from the platform you play on.
Create a new Physics Material, set friction zero and add it to your object. If your object has no friction, its speed cannot be decreased. Then, use AddForce() on Rigidbody2D to speed up.
Assuming that your ball and colliding walls have bouncy materials with no friction. Try
public float _ballSpeed = 2.5f;
Rigidbody2D _rb;
void Start()
{
_rb = GetComponent<Rigidbody2D>();
_rb.velocity = Vector2.one * _ballSpeed;
}
void Update()
{
}
From this you can control ball speed through _ballSpeed
//========== OR ==========//
If you want to retain speed even after ball destruction.
Retain _ballSpeed in any global static variable.
Suppose you have a class named Globals, declare a variable like,
public class Globals
{
public static float BALL_SPEED = 2.5f;
}
Now in Ball Script
Rigidbody2D _rb;
void Start()
{
_rb = GetComponent<Rigidbody2D>();
_rb.velocity = Vector2.one * Globals.BALL_SPEED;
}
void Update()
{
}
I make a game in Unity3D (+2D ToolKit) for iOS.
It is 2d runner/platformer with side view. So on screen is moving background and obstacles. And we control up/down the main character to overcome obstacles.
The problem is that the moving picture has a visual lag. In other words, it moves jerkily or creates the tail area of the previous frames on iOS-devices. In XCode the number of frames is 30 and over.
I have objects 'plain' with the following script:
public class Move: Monobehavior
{
private float x;
public float Speed = 128.0f;
void Start()
{
x = transform.position.x;
}
void Update()
{
x += Time.DeltaTime *Speed;
Vector3 N = transform.position;
N.x = mathf.FloorInt(x);
transform.position = N;
}
}
The question is how to make the move of background smoother, without jerks and flicker on screen while playing? Maybe the problem is in framerate parameter.
Can anybody help me to find a solution?
I'd say it's the use of the FloorInt function which will move the background only in steps of 1 which is rather not smooth. It should get better when you comment that line out. Do you have any special reason why you are doing the FloorInt there?
The use of floor will definitely hurt your performance. Not only is it one more thing to calculate, but it is actually removing fidelity by removing decimals. This will definalty make the movement look 'jerky'. Also, update is not always called on the same time inteval, depending on what else is happening during that frame, so using Time.delaTime is highly recommended. Another thing, you do not need to set variables for x and Vector3 N, when you can update the transoms position like the code below. And if you have to, you sill only need to create one variable to update, and set your position to it. The code below just updates the players x position at a given rate, based on the amount of time that has passes since the last update. There should be no 'jerky' movement. (Unless you have a serious framerate drop);
public class Move: Monobehavior
{
public float Speed = 128.0f;
void Update()
{
transform.position =
(transform.position.x + (speed*Time.DeltaTime),
transform.position.y,
transform.position.z);
}
}