How to check ground for unity2d platformer game - c#

I am trying to make a 2d plat-former where you see the player from the side. I want him to be continuously moving and you have to press space at the right time so he doesn't fall. Right now everything works but he doesn't collide with the ground. I want it to be like he's running behind a wall so I want to ignore a certain layer I have made and collide with the boxes below that. So far I have tried ray casting, watched multiple tutorials, and did box collisions. Box collisions worked but to get all the platforms counted as solid I'd need like 50 box colliders. Here is my current code:
public int playerSpeed = 10;
public int playerJumpPower = 1250;
public float moveX;
public float playerYSize = 2;
public LayerMask mainGround;
public float playerFallSpeed = 5;
void Awake(){
}
// Update is called once per frame
void Update()
{
RaycastHit2D hit = Physics2D.Raycast(transform.position, new Vector2(10, 0));
if(hit.distance < 0.7f){
print("hi");
}
Vector3 characterTargetPosition = new Vector3(transform.position.x + playerSpeed, transform.position.y, transform.position.z);
transform.position = Vector3.Lerp(transform.position, characterTargetPosition, playerSpeed * Time.deltaTime);
if(Input.GetKeyDown("space")){
// float playerTargetPosY = transform.position.y + playerJumpPower;
// Vector3 characterTargetPosition = new Vector3(transform.position.x, playerTargetPosY, transform.position.z);
// transform.position = Vector3.Lerp(transform.position, characterTargetPosition, playerJumpPower * Time.deltaTime);
gameObject.GetComponent<Rigidbody2D>().AddForce(Vector2.up * playerJumpPower);
}
//PlayerMove();
}
I have a rigidBody2D on my player so right now he just falls through the ground but the jump does work. If there is any easy way to do this. Like some script, a tutorial, or website I'm open for it. Please help.

Do you have a Rigidbody2D in your player? Things that will move usually have to have a RigidBody
(sorry for posting this as an answer. Cant comment yet)
EDIT:
try this:
Rigidbody2D rb;
void Awake()
{
rb = GetComponent<Rigidbody2D>();
}
//Physics usually are done in FixedUpdate to be more constant
public void FixedUpdate(){
if (Input.GetKeyDown("space"))
{
if(!rb.simulated)
//player can fall
rb.simulated = true;
rb.AddForce(Vector2.up * playerJumpPower);
}
else
{
//third argument is the distance from the center of the object where it will collide
//therefore you want the distance from the center to the bottom of the sprite
//which is half of the player height if the center is actually in the center of the sprite
RaycastHit2D hit = Physics2D.Raycast(transform.position, -Vector2.up, playerYSize / 2);
if (hit.collider)
{
//make player stop falling
rb.simulated = false;
}
}
}
If the player is the only thing that will collide with something you can just take out the colliders from the object that the player will not collide with.
Else you can check for the layer of the collided object with hit.collider.gameObject.layer and decide if the player will collide with that layer or not
(note that you have to compare with the index of the layer. If you want to get the index by its name you can use LayerMask.NameToLayer(/*layer name*/))
you will have to do rb.simulated = true everytime you want to do something with the RigidBody (like AddForce())
hope it helped :)

Related

How can I lock the rotation of a player in Unity?

I'm currently making a 2D game as a beginner and I made a spinning platform. But when it's rotating the player's rotation (z-axis) also changes because it's a child of the platform. I need this when I use moving platforms. Now I want to lock the z-axis of the rotation of the player. I already tried it in 3 different ways, but none of them seems to be working. Does anybody know how to do this?
These are the three ways I tried:
// 1
PlayerTrans.transform.Rotate(
PlayerTrans.transform.rotation.x,
PlayerTrans.transform.rotation.y,
0);
// 2
PlayerTrans.transform.Rotate(
PlayerTrans.transform.rotation.x,
PlayerTrans.transform.rotation.y,
0,
Space.Self);
// 3
PlayerTrans.transform.localRotation = Quaternion.Euler(new Vector3(
PlayerTrans.transform.localEulerAngles.x,
PlayerTrans.transform.localEulerAngles.y,
0f));
and this is, what my code looks like for staying on the moving platforms. I used raycasting for this:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Raycasting : MonoBehaviour
{
// Start is called before the first frame update
Transform PlayerTrans;
public float RayCastRange = 3;
void Start()
{
PlayerTrans = transform.parent;
}
// Update is called once per frame
void Update()
{
RaycastHit2D PlattformCheck = Physics2D.Raycast(transform.position, -Vector2.up, RayCastRange);
if (PlattformCheck.collider != null)
{
if (PlattformCheck.collider.gameObject.tag == "Platform")
{
PlayerTrans.transform.SetParent(PlattformCheck.collider.gameObject.transform);
}
else
{
PlayerTrans.transform.SetParent(null);
}
}
else
{
PlayerTrans.transform.SetParent(null);
}
}
}
There are 2 ways that might help you:
Just freeze the rotation from the inspector:
you can use some LookAt function (there is one for 3D but you can look and find ones for 2D) and just look at the camera.
(if you cant find it let me know and I will add it)
You should raycast directly down and then apply velocities to both objects (un-child the player from the platforms). You could do something like this for the player:
public LayerMask mask; //set ‘mask’ to the mask of the
//platform in the Unity Editor.
public Vector3 velocity;
void Update()
{
RaycastHit hit;
if (Physics.Raycast(transform.position, -Vector3.up, out hit, 0.1f, mask))
//0.1f is the distance to the platform to be able to be moved by the platform.
{
velocity = hit.collider.gameObject.GetComponent<Platform>().velocity;
}
float h = Input.GetAxis(“Horizontal”);
//this one is for CharacterController:
cc.Move(velocity);
//this one is for rigidbody:
rb.velocity = velocity;
velocity = 0;
}
It takes the velocity from the ‘Platform’ script and moves the player based on it. Now we should add the platform script. Call it ‘Platform’.
public Vector3 velocity;
public Vector3 a; //a and b are the two points you want the platform to go between.
public Vector3 b;
public float period = 2f; //the amount of seconds per cycle.
float cycles;
void Update()
{
cycles = Time.time / period;
float amplitude = Mathf.Sin(Mathf.PI * 2f * cycles);
Vector3 location = Vector3.Lerp(a, b, amplitude);
velocity = transform.position - location;
transform.position = velocity;
}
This script interpolates between the point a and b, then it finds the velocity and applies it. The player takes this velocity and it moves the player. Comment if you found an error.

How to make player stop infinite jump in unity 2d

So I'm new to unity only 2 days, and I'm having this problem of my player jumping in air. I can keep clicking the spacebar key and my player will keep jumping and not stop, I'm trying make it so the player can only jump while on the ground not the air. I been trying a lot of tutorials and most of them just made my game freeze up and not work anymore. I also been trying to find out how to use ground check but I'm still not sure on how to do that.
This is my code that I have right know.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PM : MonoBehaviour
{
public float moveSpeed;
public float jumpHeight;
Rigidbody2D rb;
void Start()
{
rb = GetComponent<Rigidbody2D>();
}
void Update() {
float moveDir = Input.GetAxis("Horizontal") * moveSpeed;
rb.velocity = new Vector2(moveDir, rb.velocity.y);
// Your jump code:
if (Input.GetKeyDown(KeyCode.Space))
{
rb.velocity = new Vector2(rb.velocity.x, jumpHeight);
}
}
}
Yes, you do need some sort of ground check. There are a lot of good tutorials online, for example, https://www.youtube.com/watch?v=c3iEl5AwUF8&t=17s ("3 ways to do a Ground Check in Unity").
To implement the simple "raycast down check", you need to assign the ground/platforms a layermask that is not the same as the player's layer. In this example, I have added a new layer named "Ground".
You can then use this simple code to do the test.
BoxCollider2D boxColliderPlayer;
int layerMaskGround;
float heightTestPlayer;
void Start()
{
rb = GetComponent<Rigidbody2D>();
// Get the player's collider so we can calculate the height of the character.
boxColliderPlayer = GetComponent<BoxCollider2D>();
// We do the height test from the center of the player, so we should only check
// halft the height of the player + some extra to ignore rounding off errors.
heightTestPlayer = boxColliderPlayer.bounds.extents.y + 0.05f;
// We are only interested to get colliders on the ground layer. If we would
// like to jump ontop of enemies we should add their layer too (which then of
// course can't be on the same layer as the player).
layerMaskGround = LayerMask.GetMask("Ground");
}
void Update()
{
float moveDir = Input.GetAxis("Horizontal") * moveSpeed;
rb.velocity = new Vector2(moveDir, rb.velocity.y);
// Your jump code:
if (Input.GetKeyDown(KeyCode.Space) && IsGrounded() )
{
rb.velocity = new Vector2(rb.velocity.x, jumpHeight);
}
}
/// <summary>
/// Simple check to see if our character is no the ground.
/// </summary>
/// <returns>Returns <c>true</c> if the character is grounded.</returns>
private bool IsGrounded()
{
// Note that we only check for colliders on the Ground layer (we don't want to hit ourself).
RaycastHit2D hit = Physics2D.Raycast(boxColliderPlayer.bounds.center, Vector2.down, heightTestPlayer, layerMaskGround);
bool isGrounded = hit.collider != null;
// It is soo easy to make misstakes so do a lot of Debug.DrawRay calls when working with colliders...
Debug.DrawRay(boxColliderPlayer.bounds.center, Vector2.down * heightTestPlayer, isGrounded ? Color.green : Color.red, 0.5f);
return isGrounded;
}
As you can see I expect the player character to have a BoxCollider2D - I guess you already have that since the character would otherwise fall through the ground). Be careful so you do not mix normal 3D colliders when you are doing 2D stuff.

Unity camera follows player script

I'm pretty new to Unity. I tried to create a script that the camera would follow the actor (with a little difference). Is there a way to improve the code? It works just fine. But I wonder if I did it the best way. I want to do it about as I wrote, so if you have any tips. Thank you
Maybe change Update to FixedUpdate ?
public GameObject player;
// Start is called before the first frame update
void Start()
{
player = GameObject.Find("Cube"); // The player
}
// Update is called once per frame
void Update()
{
transform.position = new Vector3(player.transform.position.x, player.transform.position.y + 5, player.transform.position.z - 10);
}
Making the camera following the player is quite straight forward.
Add this script to your main camera.
Drag the reference of the player object to the script and then you are done.
You can change the values in the Vector 3 depending on how far you want the camera to be from the player.
using UnityEngine;
public class Follow_player : MonoBehaviour {
public Transform player;
// Update is called once per frame
void Update () {
transform.position = player.transform.position + new Vector3(0, 1, -5);
}
}
Follows player in the back constantly when the player rotates, no parenting needed, with smoothing.
Piece of Knowledges:
Apparently, Quaternion * Vector3 is going to rotate the point of the Vector3 around the origin of the Vector3 by the angle of the Quaternion
The Lerp method in Vector3 and Quaternion stand for linear interpolation, where the first parameter gets closer to the second parameter by the amount of third parameter each frame.
using UnityEngine;
public class CameraFollow : MonoBehaviour
{
public Transform target;
public float smoothSpeed = 0.125f;
public Vector3 locationOffset;
public Vector3 rotationOffset;
void FixedUpdate()
{
Vector3 desiredPosition = target.position + target.rotation * locationOffset;
Vector3 smoothedPosition = Vector3.Lerp(transform.position, desiredPosition, smoothSpeed);
transform.position = smoothedPosition;
Quaternion desiredrotation = target.rotation * Quaternion.Euler(rotationOffset);
Quaternion smoothedrotation = Quaternion.Lerp(transform.rotation, desiredrotation, smoothSpeed);
transform.rotation = smoothedrotation;
}
}
This will always follow the player from the same direction, and if the player rotates it will still stay the same. This may be good for top-down or side-scrolling view, but the camera setup seems to be more fitting for 3rd person, in which case you'd want to rotate the camera when the player turns.
The easiest way to do this is actually not with code alone, simply make the camera a child of the player object, that way its position relative to the player will always stay the same!
If you do want to do it through code, you can change the code to be like this:
void Update()
{
Vector3 back = -player.transform.forward;
back.y = 0.5f; // this determines how high. Increase for higher view angle.
transform.position = player.transform.position - back * distance;
transform.forward = player.transform.position - transform.position;
}
You get the direction of the back of the player (opposite of transform's forward). Then you increase the height a little so the angle will be a bit from above like in your example. Last you set the camera's position to be the player's position and add the back direction multiplied by the distance. That will place the camera behind the player.
You also need to rotate the camera so it points at the player, and that's the last line - setting the camera's forward direction to point at the player.
Here is just another option. I always find it easier to have the variables which are populated in the inspector so you can adjust it and fine tune it as needed.
public GameObject player;
[SerializeField]
private float xAxis, yAxis, zAxis;
private void Update()
{
transform.position = new Vector3(player.transform.position.x + xAxis, player.transform.position.y + yAxis, player.transform.position.z + zAxis);
}

Unity OnTriggerEnter2D hit the ball to floor on high speed doesn't work

When I set the speed of Ball = 10 OnTriggerEnter2D to test the ball hit on the floor work fine, but when I set the speed higher (20), OnTriggerEnter2D doesn't work and the ball falls down through the floor
My code:
void Start () {
rigiBody = GetComponent<Rigidbody2D>();
ballLayer = 1 << LayerMask.NameToLayer("Ball");
}
void OnTriggerEnter2D(Collider2D other) {
if (other.CompareTag(Constants.FLOOR_TAG))
{
Debug.Log("FLOOR_TAG");
if (HitFloor != null)
HitFloor(this);
}
}
void FixedUpdate() {
Vector2 tempVect = Direction;
tempVect = tempVect.normalized * Speed * Time.deltaTime;
Vector2 newPos = rigiBody.position + tempVect;
rigiBody.MovePosition(newPos);
timer += Time.deltaTime;
RaycastHit2D hit = Physics2D.Raycast(newPos, Direction, Speed * Time.deltaTime * 1.2f, ~(ballLayer));
if (!hit)
return;
...
Inspector of Ball below
What's wrong with this code?
ps I'm using Unity 2017.1.1f1 Personal
You have to change the "Collision Detection" property of rigidbody. It should be "continuous" not "discrete". If you choose discrete value you are telling rigidbody to check collision in discrete time intervals. If you move in a high speed, rigidbody will probably miss collision.
Set the collision detection mode in the Rigidbody2D component to Continuous. Documentation
And maybe changing
RaycastHit2D hit = Physics2D.Raycast(newPos, Direction, Speed * Time.deltaTime * 1.2f, ~(ballLayer));
to
RaycastHit2D hit = Physics2D.Raycast(newPos, Direction, Speed * 1.2f, ~(ballLayer));
will fix the problem aswell.
Why do you cast the Ray from the newPosition? Imo. You should cast it from its current Position.
Solution of my problem was really close
A couple of lines were added and changed
add [RequireComponent(typeof(Rigidbody2D))] for class Ball
replace variable RigiBody to property
Now everything work well, and balls not fall through the floor on high speed
Code after changes look like this
[RequireComponent(typeof(Rigidbody2D))] // Added this code
public class Ball : MonoBehaviour {
private Rigidbody2D _rigiBody;
public Rigidbody2D RigidBody { //And this property
get {
if (_rigiBody == null)
_rigiBody = GetComponent<Rigidbody2D>();
return _rigiBody;
}
}

Spawn bombs and throw them to the player in Unity

I got a small arena where the player can move on. At the sides of the area there are spawners. These spawners instantiate bombs and should throw them at the player.
For the direction I actually use
transform.lookAt(playerTransform);
So this is a rough map
So the spawners are rotating around the map. They move from one point to the next point.
My bomb object got a rigidbody attached and the gravity is activated. I just need to find out how to make a spawner throwing a bomb to the player.
public class BombSpawner : MonoBehaviour
{
[Range(0, 3)]
[SerializeField]
private int nextPointIndex; // set the first targetpoint
private Vector3[] targetPoints = {
new Vector3(-15,0,15),
new Vector3(15,0,15),
new Vector3(15,0,-15),
new Vector3(-15,0,-15)};
private float movementSpeed = 10;
GameObject bombPrefab;
Transform player;
private void Start()
{
bombPrefab = Resources.Load(StringCollection.BOMB) as GameObject;
player = Globals.GetPlayerObject().transform;
}
private void Update()
{
transform.LookAt(player); // set the object rotation
Vector3 nextPoint = targetPoints[nextPointIndex]; // get the target point
transform.position = Vector3.MoveTowards(transform.position, nextPoint, movementSpeed * Time.deltaTime); // move the spawner
if (transform.position == nextPoint) // point reached? set a new point
{
if (nextPointIndex < targetPoints.Length - 1)
nextPointIndex++;
else
nextPointIndex = 0;
}
}
}
So I could write a method like this
void SpawnBomb()
{
GameObject spawnedBomb = Instantiate(bombPrefab);
}
but how do I achieve the throwing mechanic? For a first try, the targetPoint is player.position that should be fine.
You need to get the direction from spawner to the current position of the target, spawn the bomb and add force to that bomb using the direction you just got.
In order to do this you should substract your spawner's position from your target position.
Vector3 dir = target.transform.position - transform.position;
Now that you have the direction you can spawn your bomb and AddForce() to it. To add force you need to call the Rigidbody component of your spawned Bomb, like this:
spawnedBomb.GetComponent<Rigidbody>().AddForce(dir.normalized * force, ForceMode.Impulse);
Where dir is the direction towards the target (normalized - so the distance doesn't matter) and force is pretty much the speed of the bomb.
Here you can read more about Rigidbody.AddForce.

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