I'm creating a top down 2D game, where the player has to break down trees. I made it so the player casts a ray toward the mouse, and when the ray hits a tree, it should lower the tree's health. I don't get any errors when I run the game or click, but it seems like the tree isn't detecting the hits.
void Update()
{
...
if (Input.GetMouseButtonDown(0))
{
RaycastHit2D hit = Physics2D.Raycast(playerRb.transform.position, mousePosition - playerRb.transform.position, 2.0f);
if (hit.collider != null)
{
if (hit.collider == GameObject.FindWithTag("Tree"))
{
hit.collider.GetComponent<TreeScript>().treeHealth--;
}
}
}
}
Still pretty new to coding and I'm teaching myself, so please make your answer easy to understand to help me learn.
Input.mousePosition is equal to the pixel your mouse is on. This is very different than the location your mouse is pointing at in the scene. To explain further, Input.mousePosition is where the mouse is. Think about it. If the camera was facing up, the mouse positon would be the same, but where they are clicking is different.
Instead of using Input.mousePosition, You should pass this into a function called Ray Camera.ScreenPointToRay();
You just input the mouse position and then use this new ray to do the raycast.
ANOTHER EXTREMELY IMPORTANT THING 1: Do not use Camera.main in Update(), as it uses a GetComponet call, which can cause perormance decreases. Store a reference of it in your script and use that.
Extremely important thing 2: I notice you are using GetComponent to change the tree's health. This is fine, but do not use GetComponent if you don't have to.
Like this:
Camera cam;
void Start()
{
cam = Camera.main; //it is fine to use this in start,
//because it is only being called once.
}
void Update()
{
...
if (Input.GetMouseButtonDown(0))
{
Ray ray = cam.ScreenPointToRay(Input.mousePosition);
RaycastHit2D hit = Physics2D.Raycast(ray);
...
}
}
You need to convert your mouse position from screen point to world point with Z value same as the other 2D objects.
Vector3 Worldpos=Camera.main.ScreenToWorldPoint(mousePos);
Also use a Debug.DrawRay to check the Raycast
Debug.DrawRay(ray.origin, ray.direction*10000f,Color.red);
Source
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so, basically, I have created a pretty simple turret script that basically just smoothly aims at the player, so long as the player is within a certain amount of range. The problem I am having, is that the Raycast I wrote that actually checks if the 'bullet' (which is nothing - it's just a raycast), would hit the target. This means that even if the player hides behind a wall, the turret can still shoot him.
My current raycast script allows the raycast to go straight through the wall, and since I am new to Unity, I have no idea how to make it check if the first object it hits is the player, so that it cannot go through walls.
Here is my current raycast script:
void Shoot()
{
//I think the problem is here - I want the raycast to return false if it hits a wall - which has the layer "ground", and true if it hits the player. Problem is, I need to make the turret return to resting position when the player is behind a wall.
//To do this, I can just set inRange = true; But I need to be able to determine when the player is behind a wall.
LayerMask layerMask = LayerMask.GetMask("Player");
if (Physics.Raycast(transform.position, transform.TransformDirection(Vector3.forward), out RaycastHit hit, Mathf.Infinity, layerMask))
{
//This determines how much damage will the player take.
int damage = Random.Range(1, 5);
hit.collider.gameObject.GetComponent<playerMovement>().Shot(damage);
//I personally THINK this means that it only triggers collisions with the player, which is why it is not working.
// The player has layer "Player", and tag "Player", so if anyone who wants to help can figure out how to make it stop when it hits anything - and then only return true if it hit the player (meaning the player is not behind walls).
}
}
If you want to check if there is anything between the player and the Raycast, then simply remove the Layermask
Change this:
LayerMask layerMask = LayerMask.GetMask("Player");
if (Physics.Raycast(transform.position, transform.TransformDirection(Vector3.forward), out RaycastHit hit, Mathf.Infinity, layerMask))
To this:
Ray ray = new Ray(transform.position, transform.TransformDirection(Vector3.forward));
if (Physics.Raycast(ray, out RaycastHit hit) {..}
You want to
remove the check for the layer in order to hit everything with the raycast
then you can use TryGetComponent to check whether the hit object has such component attached or not
and in general instead of
transform.TransformDirection(Vector3.forward)
simply use transform.forward ;)
So something like
void Shoot()
{
if (Physics.Raycast(transform.position, transform.forward, out var hit))
{
// Without the need for any tag or layer check
// Simply check if the object you hit has a playerMovement component
// GetComponent was improved a lot lately and now uses hashes
// it's not that performance intense anymore and almost as fast as CompareTag
if(hit.gameObject.TryGetComponent<playerMovement>(out var movement)
{
int damage = Random.Range(1, 5);
movement.Shot(damage);
}
}
}
All you'd need to do is cast from the turret to the player and detect what the raycast has hit. Your current code is setting a mask to only be on the player, so it will never hit a wall. You can change your code to something like this:
private LayerMask layerMask = (1 << LayerMask.NameToLayer("Player") | (1 << LayerMask.NameToLayer("ground")));
void Update () {
if (Physics.Raycast(transform.position, transform.TransformDirection(Vector3.forward), out RaycastHit hit, Mathf.Infinity, layerMask))
{
if(hit.collider.gameObject.layer == LayerMask.NameToLayer("Player"))
{
// you can shoot as you see the player
}
else
{
// you hit the ground - player is behind a wall
}
}
}
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 casting a ray from an empty transform at the tip of a gun. The cast is to head towards the mouse position on Right Click. There is a unexpected result of the hit point being half way from expected.
I have attempted to rework the Raycasting and check out the Unity documents and forums, perhaps i am missing so simple. I have included the code of my Fire Function. Note "Raycaster" is the empty gameobject it fires from.
public void Fire(Vector3 point)
{
RaycastHit hit;
if(Physics.Raycast(Raycaster.transform.position, point, out hit))
{
Debug.DrawLine(Raycaster.transform.position, point, Color.green); //expected
Debug.DrawLine(Raycaster.transform.position, hit.point, Color.red); //actual
if(hit.rigidbody != null)
{
hit.rigidbody.AddForce(-hit.normal * weapon.Damage);
}
GameObject Impact = Instantiate(ImpactParticle, hit.point, Quaternion.LookRotation(hit.normal));
Destroy(Impact, 1f);
}
}
The first Debug.Drawline in Green is what I expect, but the second Debug.Drawline is the actual. I must be the hit.point from the Raycast but it always is half way.
Issue example, Green is expected and red is actual
I think you use world position(point). Try convert your point argument to direction.
Vector3 dir = point - Raycaster.transform.position;
Physics.Raycast(Raycaster.transform.position, dir, out hit)
I'm making a simple character that follows the player's cursor. What I also want is for when the game object "enemy" appears the character then goes to that location to alert the player. Once the enemy is gone the character continues to follow the cursor like normal. Is there a reason why my script won't work. How else can I paraphrase it?
public class FollowCursor : MonoBehaviour
{
void Update ()
{
//transform.position = Camera.main.ScreenToWorldPoint( new Vector3(Input.mousePosition.x,Input.mousePosition.y,8.75f));
if (gameObject.FindWithTag == "Enemy")
{
GameObject.FindWithTag("Enemy").transform.position
}
if (gameObject.FindWithTag != "Enemy")
{
transform.position = Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x,Input.mousePosition.y,8.75f));
}
}
}
You are not using FindWithTag correctly, as it is a method that takes a string as parameter you need to use it like this:
GameObject.FindwithTag("Something") as stated in the Unity scripting API
Now to apply this to your code you would need to do the following to set your players position based on wether or not an enemy is found (assuming this script is on your actual player object):
if(GameObject.FindWithTag("Enemy"))
{
//If an enemy is found with the tag "Enemy", set the position of the object this script is attatched to to be the same as that of the found GameObject.
transform.position = GameObject.FindWithTag("Enemy").transform.position;
}
else
{
//when no enemy with the tag "Enemy" is found, set this GameObject its position to the the same as that of the cursor
transform.position = Camera.main.ScreenToWorldPoint( new Vector3(Input.mousePosition.x,Input.mousePosition.y,8.75f));
}
However this code will just snap your player instantly to the position of the found Enemy. If this is not the desired behaviour you could use a function like Vector3.MoveTowards instead to make the player move to it gradually.
This code also has room for optimisation as searching for a GameObject every update frame is not the ideal solution. But for now it should work.
I'm going to code coding all the function for you, I'm not pretty sure about the beavihour of your code, I understand a gameobject will be attached to the mouse position, so not really following....
Vector3 targetPosition;
public float step = 0.01f;
void Update()
{
//if there is any enemy "near"/close
//targetPosition = enemy.position;
//else
//targetPosition = MouseInput;
transform.position = Vector3.MoveTowards(transform.position, targetPosition , step);
}
For the f you can use a SphereCast and from the enemies returned get the closest one.
I want to measure the distance between two points in Unity3D Game Engine using the Oculus Rift. The points are targeted by the user by looking at point A, pressing alpha1 on the keyboard and B, pressing alpha2 on the keyboard. I got this far:
#pragma strict
private var measuring = false;
private var startPoint : Vector3;
private var dist;
function Update() {
var hit : RaycastHit;
if (Input.GetKeyDown(KeyCode.Alpha1)) {
dist = 0.0f;
if (Physics.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition), hit)) {
// if (Physics.Raycast(transform.position, transform.forward, hit, 10)) {
measuring = true;
startPoint = hit.point;
}
}
if (measuring && Input.GetKeyDown(KeyCode.Alpha2)) {
if (Physics.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition), hit)) {
// if (Physics.Raycast(transform.position, transform.forward, hit, 10)) {
dist = Vector3.Distance(startPoint, hit.point);
}
}
}
function OnGUI() {
if (measuring) {
GUI.Label(Rect(50,50,180,50), "Distance: " + dist.ToString());
}
}
My problem is, that this code only works with the standard main camera object, but I want to use the Oculus integrated OVRCameraRig. I get the following exception message:
NullReferenceException: Object reference not set to an instance of an object
MeasureInGame.Update () (at Assets/MeasureInGame.js:11)
I found a solution on this site: https://kaharri.com/unity-gaming-shootingaiming-part3-oculus/ I created a ShotSpawner object as a child of OVRCameraRig (this should act like a gun in front of the camera) and changed the Raycast to
Physics.Raycast(transform.position, transform.forward, hit, 10)
to get the users view. But it also doesn't seem to work.
How can I get the aiming done with the Oculus a Main Camera. And is it correct that I strictly need to have a collider on my objects to be measured or is there a solution without collider?
Greetings
First of all - are you really using the mouse with Oculus? Of course you can, but the standard way is to look at the selected object (cursor is in the center of viewport). Cast the ray from the "middle" eye in the oculus integration - it's the object that is the parent to the left and right eyes. Use this ray instead of the one from Camera.main.ScreenPointToRay:
// add a reference to the middleEyeGameobject
// in your class and link it in the inspector
var ray=new Ray(middleEyeGameobject.transform.position, middleEyeGameobject.transform.forward);
Also, you don't have to specify the distance with hit raycast (remove the fourth parameter to Physics.Raycast).
And for the additional question yes, everything has to have a collider with Physics.Raycast. And yes, there are other ways to do this, but the built in ones (2) still require colliders (or similar), although they can be virtual, not attached to objects.
It's best to use colliders, perhaps on their own layer.
The NullReferenceException you are getting is because you are using Camera.main.ScreenPointToRay(Input.mousePosition) , camera.main uses the MainCamera tag which is not set for your OVRCameraRig. You can set tag of this camera as mainCamera if OVRCameraRig is supposed to be your mainCamera or otherwise you can take reference of this camera (OVRCameraRig) and use cameraRef.ScreenPointToRay(Input.mousePosition). :)