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How to rotate around an object without using unity's built-in functions?

i want to rotate a cube around a 1x1 pipe with arrow keys. (left and right).
The problem is i cannot use built-in functions which sets transform's position and location directly. (Such as transform.lookAt, transform.Rotate or transform.RotateAround). Because I need the vector values of rotation's euler and position for multiple stuff before i modify the value of the transform i want to rotate.
I tried different techniques but no luck so far.
I tried using sin-cos for rotating but could not figure out how to make it work for both rotation and position.
_timer += Time.deltaTime * _larvaSpeed;
float x = -Mathf.Cos(_timer) * distanceBetweenCenter;
float y = Mathf.Sin(_timer) * distanceBetweenCenter;
Here is what i want to achieve. By pressing right or left, move and rotate the object around the pipe.
The result i want. (If i pressed right arrow key a litte bit).
I would appreciate any help. Thank you!

here is the solution using circle mathematics and I strongly recommended not use it, it's just to understand the circular move using circle equation as #FaTaLL ask in the comments
Circle equation...
(x1 - x2)^2 + (y1 - y2)^2 = r^2
x1, y1 is the cube position
x2, y2 is the pipe position
r is the distance between cube and pipe;
using UnityEngine;
public class Rotating : MonoBehaviour
{
public GameObject pipe;
public float Delta;
Vector3 nextpos;
bool compareY;
bool next;
int switchx;
float storeVarAxis;
float x, y, r;
private void Start()
{
next = true;
switchx = 1;
compareY = true;
x = transform.position.x - pipe.transform.position.x;
y = transform.position.y - pipe.transform.position.y;
storeVarAxis = y;
r = Mathf.Sqrt(x * x + y * y);
}
private void Update()
{
if (next)
{
if (compareY == true)
{
y -= Delta * Time.deltaTime;
if (y <= -storeVarAxis)
{
y = -storeVarAxis;
compareY = false;
switchx = -1;
}
}
else
{
y += Delta * Time.deltaTime;
if (y >= storeVarAxis)
{
y = storeVarAxis;
compareY = true;
switchx = 1;
}
}
float v = r * r - y * y;
x = Mathf.Sqrt(Mathf.Abs(v));
nextpos = new Vector3(pipe.transform.position.x + x * switchx, pipe.transform.position.y + y, transform.position.z);
next = false;
}
transform.position = Vector3.MoveTowards(transform.position, nextpos, 1f * Time.deltaTime);
if(Vector3.Distance(transform.position, nextpos) < .05) transform.position = nextpos;
if (transform.position.x.Equals(nextpos.x) && transform.position.y.Equals(nextpos.y)) next = true;
}
}
well, the recommended way is using this simple script
using UnityEngine;
public class Rotating : MonoBehaviour
{
public float speed;
public GameObject pipe;
float r, angle;
Vector3 startpos;
private void Start()
{
r = Mathf.Abs(transform.position.y - pipe.transform.position.y);
angle = 0;
transform.position = pipe.transform.position;
startpos = transform.position;
}
void Update()
{
angle = angle + speed * Time.deltaTime;
transform.rotation = Quaternion.EulerAngles(0,0, angle);
transform.position = startpos + (transform.rotation * new Vector3(r, 0, 0));
}
}

I think Quaternion * Vector3 is what you are looking for. Luckily the box's rotation in its own local coordinates is the same rotation you need to apply to the box's position.
public float speed; //how fast to rotate
public float radius; //radius of the cylinder
public float angle; //angle around it
void Update()
{
if (Input.GetKey(KeyCode.LeftArrow))
{
angle = angle + speed * Time.deltaTime;
}
if (Input.GetKey(KeyCode.RightArrow))
{
angle = angle - speed * Time.deltaTime;
}
//figure out the rotation (from euler angles i guess??)
var quat = Quaternion.EulerAngles(new Vector3(0, angle, 0));
//ok uh what is the box position?? lets just multiply
var unrotated_position = new Vector3(radius, 0, 0);
var rotated_position = quat * unrotated_position;
this.transform.position = rotated_position;
//oh yea and also rotate the box in its own local coordinates
this.transform.rotation = quat;
}

Cylinder Snapping into place during Quaternion.RotateTowards

What I am trying to do is have a pillar in the center of a scene, and what i think is happening is the quaternion.RotateTowards is receiving a different starting/initial quaternion than the action which is causing it to snap/teleport into a different location which then starts to move to the next. I thought it may be because i'm misunderstanding how quaternions are handled in unity, so i've tried messing with normalizing it, but i can't seem to get any change on the teleport.
The goal is to attach this scrip to a simple 3D cylinder and have it wobble basically, where there will be a player on top of it trying to stay on it. However I can't seem to figure out why it is teleporting and was hoping for a second set of eyes.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlatformWobble : MonoBehaviour
{
public float timeDelay = 0;
public float rRange = 0.5f;
public float maxRotation = 20.0f;
public float rotRate = 0.05f;
private bool wobble = false;
private Vector3 randomRotation;
private Quaternion rotation;
private Quaternion destination;
private float x, y, z;
private bool inPlace;
private void Start()
{
randomRotation = new Vector3();
inPlace = true;
}
// Update is called once per frame
void FixedUpdate()
{
if (inPlace)
{
destination = RotateRandomly();
inPlace = false;
}
transform.localRotation = Quaternion.RotateTowards(transform.localRotation, destination, rotRate * Time.deltaTime);
if (transform.localRotation == destination)
{
inPlace = true;
}
}
//This will grab the rotation of the object and move it randomly, but won't exceed maxRotation;
Quaternion RotateRandomly()
{
randomRotation = new Vector3(Random.Range(-rRange, rRange), Random.Range(-rRange, rRange), Random.Range(-rRange, rRange));
rotation = transform.localRotation;
x = rotation.x + randomRotation.x;
if(x >= maxRotation && x <= 360 - maxRotation) { x = rotation.x; }
y = rotation.y + randomRotation.y;
if (y >= maxRotation && y <= 360 - maxRotation) { y = rotation.y; }
z = rotation.z + randomRotation.z;
if (z >= maxRotation && z <= 360-maxRotation) { z = rotation.z; }
return new Quaternion(x, y, z, transform.localRotation.w);
}
}

Your quaternion calculations are incorrect: quaternions do not hold angles, instead, they hold the representation of a rotation about an axis. I emphasized "representation" because it is a little complicated...
The x, y, z components of a quaternion hold the rotation axis unit vector scaled by the sine of the half angle of rotation. The w component holds the cosine of the half angle. That is...
// NOTE: rotationAngle is in radians rather than degrees
Quaternion MakeQuaternion (Vector3 rotationAxis, float rotationAngle)
{
float c = Mathf.Cos (rotationAngle / 2);
float s = Mathf.Sin (rotationAngle / 2);
Vector3 v = rotationAxis.normalized * s;
return new Quaternion (v.x, v.y, v.z, c);
}
Now, the tricky part for your problem is coming up with the rotation axis and angle for the desired effect.
One solution (if you wish to stick to Euler angles) is to compute quaternions for each Euler rotation and then combine them:
Quaternion EulerToQuat (float XAngle, float YAngle, float ZAngle)
{
Quaternion X = MakeQuaternion (Vector3.right, XAngle);
Quaternion Y = MakeQuaternion (Vector3.up, YAngle);
Quaternion Z = MakeQuaternion (Vector3.forward, ZAngle);
// combine the rotations such that the object is first rotated about the Z axis,
// then about the Y axis, then the X (ie, reverse order of multiplication).
// Reminder: quaternion multiplicate is not commutative: order matters, so if this
// is not the order you want, just siwtch things around
rotate X * Y * Z;
}

FixedUpdate doesn't get called every render frame, only on physics frames. You need a way to tell Unity to have each frame showing the rotation change, rather than only updating the rendering when the physics frame has just run.
That is what Rigidbody.MoveRotation is for. Cache a reference to the Rigidbody, calculate the new global rotation it should have, then call MoveRotation:
private Rigidbody rb;
private void Start()
{
randomRotation = new Vector3();
inPlace = true;
rb = GetComponent<Rigidbody>();
}
// ...
// Update is called once per frame
void FixedUpdate()
{
if (inPlace)
{
destination = RotateRandomly();
inPlace = false;
}
Quaternion newLocalRot = Quaternion.RotateTowards(transform.localRotation,
destination, rotRate * Time.deltaTime);
Quaternion newGlobalRot = transform.parent.rotation * newLocalRot;
rb.MoveRotation(newGlobalRot);
if (transform.localRotation == destination)
{
inPlace = true;
}
}

Rotate rigidbody with moverotation in the direction of the camera

I want to use moverotation to rotate the object in the direction of the Main Camera, like a common third person shooter, but I don't know how to set the quaternion values or otherwise
`using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class movimento : MonoBehaviour
{
[SerializeField] float walk = 1;
[SerializeField] float run = 2;
Vector3 movement = Vector3.zero;
private Rigidbody rig;
// Start is called before the first frame update
void Start()
{
rig = GetComponent<Rigidbody>();
}
// Update is called once per frame
void Update()
{
if (Input.GetKeyDown(KeyCode.LeftShift)) walk = (walk + run);
if (Input.GetKeyUp(KeyCode.LeftShift)) walk = (walk - run);
float Horizontal = Input.GetAxis("Horizontal");.
float Vertical = Input.GetAxis("Vertical");
movement = Camera.main.transform.forward * Vertical + Camera.main.transform.right * Horizontal;
float origMagnitude = movement.magnitude;
movement.y = 0f;
movement = movement.normalized * origMagnitude;
}
private void FixedUpdate ()
{
rig.MovePosition(rig.position + movement * walk * Time.fixedDeltaTime);
Quaternion rotation = Quaternion.Euler(???);
rig.MoveRotation(rig.rotation * rotation);
}
}`

i use a coroutine to do smooth rotation. I use Quaternion.LookRotation for the job.
so you indicate the position of object to look at and the duration of animation. Here you want to rotate face to the main camera
StartCoroutine(SmoothRotation(Camera.main.transform, 3f));
:
:
IEnumerator SmoothRotation(Transform target, float duration)
{
float currentDelta = 0;
var startrotation = transform.rotation;//use your rigisbody if you want here i use the gameobject
var LookPos = target.position - transform.position;
var finalrot = Quaternion.LookRotation(LookPos);
while (currentDelta <= 1f)
{
currentDelta += Time.deltaTime / duration;
transform.rotation = Quaternion.Lerp(startrotation, finalrot, currentDelta);//
yield return null;
}
transform.rotation = finalrot;
}
if you want to see (in scene when running) where your camera points just add this line of code in update():
Debug.DrawRay(Camera.main.transform.position, Camera.main.transform.TransformDirection(Vector3.forward) * 10f, Color.black);
if you want to point in same direction tha nthe Camera just change the line of finalrot in SmoothRotation Method:
var finalrot = Camera.main.transform.rotation;
you dont need to calculate the LookPos
for your problem of crazy rotation, i suggest you to reset rotation x and z
direction = hit.transform.position - transform.position;
Quaternion rotation = Quaternion.LookRotation(direction);
rotation.x = 0f;
rotation.z = 0f;
a tips to detect object what you want with the raycast inside spere : Physics.OverlapSphere: you could select what you want to cast when using the optional parameter layermask
private void DetectEnemy(Vector3 center, float radius)
{
var hitColliders = Physics.OverlapSphere(center, radius );
for (var i = 0; i < hitColliders.Length; i++)
{
print(hitColliders[i].name + "," + hitColliders[i].transform.position);
// collect information on the hits here
}
}

I created a raycast from the camera, and I would like to rotate the rigidbody to where the raycast is pointing but if i launch unity, it rotated wildly. What is the error?
Vector3 direction;
Vector3 rayDir = new Vector3(Screen.width/2,Screen.height/2);
void Update()
Ray ray = Camera.main.ScreenPointToRay(rayDir);
Debug.DrawRay(ray.origin, ray.direction * 10, Color.yellow);
RaycastHit hit = new RaycastHit ();
direction = hit.point - transform.position;
private void FixedUpdate ()
Quaternion rotation = Quaternion.LookRotation(direction);
rig.MoveRotation(rig.rotation * rotation);

Add a character controller component, this is what is for. See:
https://docs.unity3d.com/Manual/class-CharacterController.html

Unity 2D Raycasting from a Rotating Transform

I'm trying to create a vision field in Unity 2d. I'm projecting raycasts from a rotating gameobject which rotates according to where the character is looking. However this character moves back and forth so when they are moving left I set the transform.scale to -1. The problem is when I do this the raycasts don't change direction along with the character and stay pointing right! Here is the code, I'm probably missing something obvious! Any help would be appreciated!
Transform parent;
float vision_angle_ = 50;
float direction;
Vector3 angle;
Vector2 position;
Quaternion q;
int x = 10;
void Start ()
{
parent = transform.parent;
}
void Update ()
{
direction = parent.GetComponent<Behaviour>().direction;
angle = new Vector2 (x, Mathf.Tan ((vision_angle_) * .5f * Mathf.Deg2Rad) * x);
q = Quaternion.AngleAxis (1, -transform.forward);
position = new Vector2 (transform.position.x, transform.position.y);
for (float i = 0; i < 50; i++) {
angle = q * angle;
RaycastHit2D tile_hit = Physics2D.Raycast (position, transform.TransformDirection (angle), 10);
Debug.DrawRay (position, transform.TransformDirection (angle), Color.green);
}
}

TransformDirection doesn't take the scale of your transform into account. You can adjust to compensate:
Vector2 direction = transform.TransformDirection(angle);
if (transform.localScale.x < 0f) {
direction.x = -direction.x;
}
RaycastHit2D tile_hit = Physics2D.Raycast(position, direction, 10);

Adding additional vertical velocity in projectile motion Unity3D

I have my point of projectile at some height above ground and my enemy(that are moving from right to left and towards the shooting point at horizontal axis) are at ground.The projectile motion that I have it shoots directly in downward motion at angle facing the enemy but I want the projectile to first go upwards and then shoot the enemy.
I have attached the snapshot below:
Here is my code:
using UnityEngine;
using System.Collections;
public class bullet : MonoBehaviour {
public Transform target;
private Transform mytransform;
public GameObject bulletprefab;
public GameObject enemyprefab;
private gamenemy e;
public float firingAngle = 20;
public float gravity = 9.8f;
void Awake()
{
mytransform = transform;
}
// Use this for initialization
void Start () {
mytransform.LookAt(target);
StartCoroutine (project ());
//follow();
}
IEnumerator project()
{ yield return new WaitForSeconds(0.25f);
float target_Distance = Vector3.Distance(mytransform.position * target_Distance , target.position);
// Calculate the velocity needed to throw the object to the target at specified angle.
float projectile_Velocity = target_Distance / (Mathf.Sin(2 * target_Distance * Mathf.Deg2Rad) / gravity);
// Extract the X Y componenent of the velocity
float Vx = Mathf.Sqrt(projectile_Velocity) * Mathf.Cos(target_Distance * Mathf.Deg2Rad);
float Vy = Mathf.Sqrt(projectile_Velocity) * Mathf.Sin( 1/target_Distance * Mathf.Deg2Rad);
// Calculate flight time.
float flightDuration = target_Distance / Vx;
// Rotate projectile to face the target.
mytransform.rotation = Quaternion.LookRotation(target.position - mytransform.position);
float elapse_time = 0;
while (elapse_time < flightDuration)
{
mytransform.Translate(0, (Vy - (gravity * elapse_time)) * Time.deltaTime, Vx * Time.deltaTime);
elapse_time += Time.deltaTime;
yield return null;
}
}
Snapshot of how it is with given code:
This is how I want it to be:

Rather than calculating the movement in your code, look at using a Rigidbody on your projectile. Then at the point of firing, apply a force relative to the initial trajectory (i.e direction the gun barrel is facing) and also have gravity affect your bullet.
More on Rigidbodies