XNA c# Lerping -- Make 3d object follow another 3d object - c#

I am making a game where an enemy AI follows a player 3d object. However, my enemy object spasms sometimes when following the player and freaks out. I think my issue may be somewhere in my dot product or my cross product math. Here is my code from my enemy class:
//here I get the direction vector in between where I am pointing and where my enemy is located at
Vector3 midVector = Vector3.Normalize(Vector3.Lerp(Vector3.Normalize(world.Forward), Vector3.Normalize(Vector3.Subtract(p.position,this.position)), angleVelocity));
//here I get the vector perpendicular to this middle vector and my forward vector
Vector3 perp=Vector3.Normalize(Vector3.Cross(midVector, Vector3.Normalize(world.Forward)));
//here I am looking at my quaternion and I am trying to rotate it about the axis (my perp vector) with an angle that I determine which is in between where I am facing and the midVector
float angle=(float)Math.Acos(Vector3.Dot(world.Forward,midVector));
//Console.WriteLine(angle);
Quaternion quaternion2 = Quaternion.CreateFromAxisAngle(perp, angle);
quaternion = quaternion * quaternion2;
//here I am simply scaling my world matrix, implementing my quaternion, and translating it to my position
world = Matrix.CreateScale(scale) * Matrix.CreateFromQuaternion(quaternion) * Matrix.CreateTranslation(position);
//here i move myself forward in the direciton that I am facing
MoveForward(ref position, quaternion, velocity);
}
private void MoveForward(ref Vector3 position, Quaternion rotationQuat, float speed)
{
Vector3 addVector = Vector3.Transform(new Vector3(0, 0, -1), rotationQuat);
position += addVector * speed;
}
public override void update()
{
base.update();
}
}

Related

Unity - Virtual Joystick - Camera rotation

I have a virtual movement joystick that I'm using to control the movement of a player object which works fine, the code for this is below.
The problem I have is when I rotate the camera within game mode (or device) the direction is not adjusted according to the cameras rotation, exactly like is shown in this post here that I looked through to try and understand the problem.
I realise I need to rotate my movement around the forward direction the camera is facing which I tried to do with the bottom snippet of code however this yields really strange behavior when the player object moves incredibly fast and eventually unity becomes unresponsive, so something is being incorrectly multiplied I guess.
Could anybody point out where I'm going wrong please? ta !
Edit - Modified to potential answer
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using EasyJoystick;
public class NewJoystick : MonoBehaviour
{
[SerializeField] private float speed;
[SerializeField] private Joystick1 joystick;
[SerializeField] Camera MainCam;
private Rigidbody RB;
private Transform cameraTransform;
// Start is called before the first frame update
void Start()
{
cameraTransform = MainCam.transform;
}
void Awake()
{
RB = gameObject.GetComponent<Rigidbody>();
}
// Update is called once per frame
void Update()
{
float xMovement = joystick.Horizontal();
float zMovement = joystick.Vertical();
Vector3 inputDirection = new Vector3(xMovement, 0, zMovement);
//Get the camera horizontal rotation
Vector3 faceDirection = new Vector3(cameraTransform.forward.x, 0, cameraTransform.forward.z);
//Get the angle between world forward and camera
float cameraAngle = Vector3.SignedAngle(Vector3.forward, faceDirection, Vector3.up);
//Finally rotate the input direction horizontally by the cameraAngle
Vector3 moveDirection = Quaternion.Euler(0, cameraAngle, 0) * inputDirection;
RB.velocity = moveDirection * speed;
}
}
I tried this in the update loop -
var Direction = transform.position += new Vector3(xMovement, 0f,zMovement); //* speed * Time.deltaTime;
Vector3 newDir = MainCam.transform.TransformDirection(Direction);
transform.position += new Vector3(newDir.x, 0f,newDir.z) * speed * Time.deltaTime;
Well, here is a simple idea for how to solve it. At least this is how I did it, and it seems to work ever since.
First, you need to get the joystick input, like you did. Both axis input value should be between -1 and 1. This actually determines the direction itself, since the horizontal axis gives you the X coordinate of a vector and the vertical gives you the Y coordinate of that vector. You can visualize it easily:
Mind, that I just put up some random values there, but you get the idea.
Now, your problem is, that this angle you get from your raw input is
static in direction, meaning that it doesn't rely on the camera's face
direction. You can solve this problem by "locking it to the camera",
or in other words, rotate the input direction based on the camera
rotation. Here's a quick example:
//Get the input direction
float inputX = joystick.Horizontal();
float inputY = joystick.Vertical();
Vector3 inputDirection = new Vector3(inputX, 0, inputY);
//Get the camera horizontal rotation
Vector3 faceDirection = new Vector3(cameraTransform.forward.x, 0, cameraTransform.forward.z);
//Get the angle between world forward and camera
float cameraAngle = Vector3.SignedAngle(Vector3.forward, faceDirection, Vector3.up);
//Finally rotate the input direction horizontally by the cameraAngle
Vector3 moveDirection = Quaternion.Euler(0, cameraAngle, 0) * inputDirection;
IMPORTANT: The code above should be called in the Update cycle, since that is where you get the input information.
After this, you can work with moveDirection to move your player. (I suggest using physics for moving, instead of modifying its position)
Simple moving example:
public RigidBody rigidbody;
public Vector3 moveDirection;
public float moveSpeed = 5f;
void FixedUpdate()
{
rigidbody.velocity = moveDirection * moveSpeed;
}

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);
}

Enemy shooting at player position

I'm creating a simple Bullet Hell game and I'm testing some things out. I want the enemy bullets to shoot towards the player as soon as he fires.
I tried a bunch of Quaternion methods including LookTowards, FromToRotation, AngleAxis, (etc...) and none seemed to work.
void Start () {
...
StartCoroutine("Shooting");
}
IEnumerator Shooting()
{
while(dead != true)
{
Vector3 position = new Vector3(rb.position.x, rb.position.y - 5f, 0);
Instantiate(Ebullet, position, Quaternion.Euler(0, 0, player.transform.position.x));
yield return new WaitForSeconds(t);
}
}
I expected the bullets to move directly to the player's last known position, instead the enemy shoots at a wrong angle and everytime the player moves, the angle changes according to the the player's left or right movement.
Since you are making a 2D game, instead of:
Instantiate(Ebullet, position, Quaternion.Euler(0, 0, player.transform.position.x);
Try:
Vector3 direction = player.transform.position-transform.position;
direction .Normalize();
float rotation = Mathf.Atan2(direction .y, direction .x) * Mathf.Rad2Deg;
Instantiate(Ebullet, position, Quaternion.Euler(0f, 0f, rotation - 90));

Player rotation and camera rotation

i want the player to look into the direction, the camera is looking.
The camera follows the player (3rd person game style).
I've tried it with
transform.localRotation = new Quaternion(transform.localRotation.x,
cameraMain.transform.localRotation.y,
transform.localRotation.z,
transform.localRotation.w);
but it doesn't work.
Sometimes the player starts rotating the other direction.
the following code will make the object (specified in the parameter) face in the direction of where the main camera is looking:
public void lookInDirectionOfCamera(Transform object) {
RayCastHit hit;
if (Physics.raycast(cameraMain.transform.position, cameraMain.transform.forward, out hit)) {
object.forward = hit.point - object.position;
}else { //if the raycast didnt hit anything, make the object face 100 units in front of the camera
Vector3 point = Camera.main.transform.position + Camera.main.transform.forward * 100;
object.forward = point - object.position;
}
}
This will make the player face the point that is forward to the camera. If you just want them to have the same rotation in the y-axis don't use Quaternions!
Instead, you can just do it with Euler angles:
transform.eulerAngles = new Vector3(transform.eulerAngles.x,
cameraMain.transform.eulerAngles.y,
transform.eulerAngles.y);
The reason not to use transform.localRotation is because that is a Quaternion. The y component in a Quaternion is not the same as the y-axis in a Euler angle (what you are used to seeing), Quaternions are very confusing so you should almost never set individual values in them. If you want to edit them only use the built-in methods.
Get the direction the camera is looking with cameraMain.transform.forward, make a copy with a y value of zero, then use Quaternion.SetLookRotation to look in that direction with the global up direction.:
Vector3 cameraDirection = cameraMain.transform.forward;
Vector3 characterLookDirection = new Vector3(cameraDirection.x,
0f,
cameraDirection.z);
Quaternion newRotation = new Quaternion();
newRotation.SetLookRotation(characterLookDirection, Vector3.up);
transform.rotation = newRotation;

Unity3D - Why doesn't my player rotate properly?

I'm building a top down shooter and so I have my camera above my player and the map. Here's the code I've written in the player controller script for movement:
public class playerMovement : MonoBehaviour {
public float speed;
private Camera mainCamera;
void Start () {
mainCamera = FindObjectOfType<Camera>();
}
// Update is called once per frame
void Update () {
// player movement
transform.Translate(speed * Input.GetAxis("Horizontal") * Time.deltaTime, 0f, speed * Input.GetAxis("Vertical") * Time.deltaTime);
// Camera Ray casting
Ray cameraRay = mainCamera.ScreenPointToRay(Input.mousePosition);
Plane groundPlane = new Plane(Vector3.up, Vector3.zero);
float rayLength;
if (groundPlane.Raycast(cameraRay, out rayLength)) {
Vector3 look = cameraRay.GetPoint(rayLength);
Debug.DrawLine(cameraRay.origin, look, Color.red);
transform.LookAt(new Vector3(look.x, transform.position.y, look.z));
}
}
}
I want to be able to move the player using the WASD keys and also rotate following the direction on where the mouse is, however I don't want the rotation of the player to change the direction of the keys, I need the player to move forwards if the W key is pressed no matter which way the player is facing.
However for some reason my code makes the player move forwards depending on which way it is facing which I don't want.
How can I fix this?
The problem is that your transform.Translate call is in "self" space. Forward, backward, left, right are all relative to the direction the transform is facing. That is why your player is moving relative to the facing direction.
If you want to translate relative to "global" or "world" space, you have to add an additional parameter.
// player movement
transform.Translate(speed * Input.GetAxis("Horizontal") * Time.deltaTime,
0f,
speed * Input.GetAxis("Vertical") * Time.deltaTime,
Space.World);
Note the Space.World parameter at the end, to set the world coordinate system.
You can find more in the Unity docs here: https://docs.unity3d.com/ScriptReference/Transform.Translate.html
You need to look at the difference between local and global coordinate systems.
Right now your WASD keys are moving the player character according to global coordinates, and you want the WASD movement to be dependant on the player's orientation so you need to use a local coordinate system.
http://wiki.unity3d.com/index.php?title=Converting_Between_Coordinate_Systems

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