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How to realistically reflect a 3d sphere in Unity with C#

I've been trying to realistically reflect a 3d sphere on the walls of a box for a while now in Unity. For some reason, the reflection is generally correct, but when the ball hits a wall in certain directions, the reflection is incorrect.
To illustrate what happens to the ball upon hitting a wall: T = top wall, R = right wall, L = left wall, and B = bottom wall. Let r = the ball comes/goes to the right, l = for the left, and s = the ball stops/slows down significantly. The instructions below take this format: Xyz, where X = the wall the ball is about to hit, y = the ball's initial direction, z = the reflection. The game has a top-down perspective, and the instructions are based on the wall's perspective. I'm also new to C#, so the code is potentially eye burning.
Instructions: Tll, Trl; Bll, Brl; Rls or after hitting another wall Rlr, Rrl; Lls or after hitting another wall Llr, Lrl
Generally, when the ball stops, it jumps in the air. I wonder if this is because the angle reflects along the wrong axis, but why would this only sometimes happen? Also, when only one key is held, the ball bounces back and forth until it leaves the arena. I know about discrete and continuous hit detection, and the setting is on discrete, but the walls generally contain the ball well enough, with this case being the exception.
What I tried:
Figuring out how to use Vector3.Reflect. I do not understand what variables this function should contain and how to apply this to my code. I did look at the Unity Documentation page for help, but it did not answer my question.
Changing the negative signs, as the angle has to be a reflection on the y-axis, and this does change how the reflections work, but does not solve the problem. The current way the negatives are ordered are the most ideal I found.
Giving the ball a physics material for bounciness.
Adding a small number to the denominator in the arctan equation to help prevent a division by zero. This did not help at all.
Creating different equations (basically changing the negatives) for varying combinations of positive and negative accelerations. Since there is a certain positive or negative acceleration associated with each button press (see Movement script), and there seems to be an issue with said signs, I wondered if associating each acceleration with its own set of equations could solve the problem. It did not work.
Checked if the walls were at different angles.
Deleting the variables xA and yA, or placing them in different spots.
Experimented with finding the speed of the object, but had no idea how to implement it.
The code for the Movement script for the player named Controller:
public class Movement : MonoBehaviour
{
public static float xAcceleration = 0.0f;
public static float yAcceleration = 0.0f;
// Update is called once per frame
void Update()
{
if (Input.GetKey(KeyCode.W)) //If the key W is pressed:
{
Vector3 position = this.transform.position; //Variable position is set to transform the players placement in the game.
if (yAcceleration >= -5 && yAcceleration <= 5) //If the y vector of the acceleration is >= -5 and <= 5:
{
yAcceleration = yAcceleration + 0.01f; //The y vector of the acceleration increases by 0.01 as long as the key W is pressed.
}
position.z = position.z + (0.1f * yAcceleration); //The position of the object on the z-axis (pretend it is the y-axis in the game world) is transformed by its original position plus its speed times its yAcceleration.
this.transform.position = position; //The gameObject is now transformed to a position equal to the variable position by the z-axis.
}
else //If the key W is let go of:
{
Vector3 position = this.transform.position;
position.z = position.z + (0.1f * yAcceleration);
this.transform.position = position; //The position of the gameObject continues to update, but its acceleration does not change. Basically, it continues to move forward.
}
//The rest of the code is very similar to the above, but I included it just in case there was something wrong.
if (Input.GetKey(KeyCode.S))
{
Vector3 position = this.transform.position;
if (yAcceleration >= -5 && yAcceleration <= 5)
{
yAcceleration = (yAcceleration) - 0.01f;
}
position.z = position.z + (0.1f * yAcceleration);
this.transform.position = position;
}
else
{
Vector3 position = this.transform.position;
position.z = position.z + (0.1f * yAcceleration);
this.transform.position = position;
}
if (Input.GetKey(KeyCode.A))
{
Vector3 position = this.transform.position;
if (xAcceleration >= -5 && xAcceleration <= 5)
{
xAcceleration = (xAcceleration) - 0.01f;
}
position.x = position.x + (0.1f * xAcceleration);
this.transform.position = position;
}
else
{
Vector3 position = this.transform.position;
position.x = position.x + (0.1f * xAcceleration);
this.transform.position = position;
}
if (Input.GetKey(KeyCode.D))
{
Vector3 position = this.transform.position;
if (xAcceleration >= -5 && xAcceleration <= 5)
{
xAcceleration = (xAcceleration) + 0.01f;
}
position.x = position.x + (0.1f * xAcceleration);
this.transform.position = position;
}
else
{
Vector3 position = this.transform.position;
position.x = position.x + (0.1f * xAcceleration);
this.transform.position = position;
}
}
}
This is the code for the collider and reflection:
public class Collider : MonoBehaviour
{
public float xA;
public float yA;
void OnCollisionEnter(Collision collision) //If a gameObject enters the collision of another object, this immediately happens once.
{
if (gameObject.tag == "Boundary") //If the gameObject has a tag named Boundary:
{
yA = -Movement.yAcceleration; //yA stores the value of yAcceleration after being called from script Movement as a negative. Its a reflection.
Movement.xAcceleration = (Movement.xAcceleration * -Mathf.Atan(yA / Movement.xAcceleration)); //xAcceleration is changed based on this equation: A * artan(A_y / A_x). The 0.000001 was here, adding to A_x to help prevent a 0 as the denominator.
xA = Movement.xAcceleration; //This is declared now...
Movement.yAcceleration = (Movement.yAcceleration * Mathf.Atan(Movement.yAcceleration / xA)); //This uses xA because Movement.xAcceleration is changed, and the yAcceleration calculation is based on the xAcceleration prior the collision.
}
}
void OnCollisionStay(Collision collision)
{
if (gameObject.tag == "Boundary")
{
yA = Movement.yAcceleration; //The same thing happens as before.
Movement.xAcceleration = (Movement.xAcceleration * -Mathf.Atan(yA / Movement.xAcceleration));
xA = Movement.xAcceleration;
Movement.yAcceleration = (Movement.yAcceleration * Mathf.Atan(Movement.yAcceleration / xA));
Movement.xAcceleration = -Movement.xAcceleration / 2; //On collision, the ball is reflected across the x-axis at half its speed.
Movement.yAcceleration = Movement.yAcceleration / 2; //yAcceleration is half its original value.
}
}
}
The picture below is the game setup. I apologize that it is a link; I do not have enough Reputation to merit a loaded image on this page. Also, if anything is unclear, please message me.
https://i.stack.imgur.com/VREV4.png
I would really appreciate the help. Thanks!

One very important note here: As soon as there is any Rigidbody involved you do not want to set any values through the .transform - This breaks the physics and collision detection!
Your Movement should rather alter the behavior of the Rigidbody e.g. by simply changing its Rigibody.velocity
I would then also place the collision check directly into the balls's component and check whether you hit a wall ("Boundary")
Then another note: Your code is currently frame-rate dependent. It means that if your target device runs with only 30 frames per second you will add 0.3 per second to the acceleration. If you run however on a more powerful device that manages to run with 200 frames per second then you add 2 per second.
You should rather define the de/increase per second and multiply it by Time.deltaTime
All together maybe something like this
public class Movement : MonoBehaviour
{
// Adjust these settings via the Inspector
[SerializeField] private float _maxMoveSpeed = 5f;
[SerializeField] private float _speedIncreasePerSecond = 1f;
// Already reference this via the Inspector
[SerializeField] private Rigidbody _rigidbody;
private void Awake()
{
if(!_rigidbody) _rigidbody = GetComponent<Rigidbody>();
}
// Get User Input in Update
private void Update()
{
var velocity = _rigidbody.velocity;
velocity.y = 0;
if (Input.GetKey(KeyCode.W) && velocity.z < _maxMoveSpeed)
{
velocity.z += _speedIncreasePerSecond * Time.deltaTime;
}
if (Input.GetKey(KeyCode.S) && velocity.z > -_maxMoveSpeed)
{
velocity.z -= _speedIncreasePerSecond * Time.deltaTime;
}
if (Input.GetKey(KeyCode.A) && velocity.x > -_maxMoveSpeed)
{
velocity.x -= _speedIncreasePerSecond * Time.deltaTime;
}
if (Input.GetKey(KeyCode.D) && velocity.x < _maxMoveSpeed)
{
velocity.x += _speedIncreasePerSecond * Time.deltaTime;
}
// clamp to the max speed in case you move diagonal
if(velocity.magnitude > _maxMoveSpeed)
{
velocity = velocity.normalized * _maxMoveSpeed;
}
_rigidbody.velocity = velocity;
}
}
And then finally simply add a PhysicsMaterial with desired settings to the walls and ball.
I used Friction = 0f and Bounciness = 0.7f for ball and walls. For slow movements you also might want/have to adjust the Bounce Threshold in the Project's Physics Settings otherwise there will be no bouncing if the velocity is smaller then 2 by default.
This depends a bit on your definition of "realistic". I disabled gravity so the ball also has no rotation and angular friction:

How to smooth out 2D rotation in C#?

I'm making a 2D game in Unity and one feature I'm trying to implement is flipping the player if the mouse position is over 90 meaning he is always facing the direction of the mouse.
Vector3 mousePosition = UtilsClass.GetMouseWorldPosition();
Vector3 aimDirection = (mousePosition - transform.position).normalized;
float angle = Mathf.Atan2(aimDirection.y, aimDirection.x) * Mathf.Rad2Deg;
Vector3 aimLocalScale = Vector3.one;
if (angle > 90 || angle < -90)
{
rotate = true;
}
else
{
rotate = false;
}
gameObject.transform.localScale = aimLocalScale;
if (rotate == true)
{
transform.Rotate(0f, 180f, 0f);
}
else
{
transform.Rotate(0f, 0f, 0f);
}
However, one problem I am having is that one, it's very finicky and if you go too fast the player is looking in the wrong direction, and two, if you look straight up, he doesn't know exactly where to look and keeps snapping left and right really fast.
Does anyone know a way to fix this allowing for a smoother more functional flipping?

Try flipping the sprite by adjusting its scale from 1 to -1. Then implement that into a FlipSprite() method and just call it when you want to flip it

So if you want to flip and sprite one approach could be to inverse the localScale of the sprite, like this:
private void FlipSprite()
{
// Multiply the player's x local scale by -1.
Vector3 flippedScale = transform.localScale;
flippedScale.x *= -1;
transform.localScale = flippedScale;
}
I suggest you to keep a boolean variable like isFacingRight to keep tracking the direction the sprite is looking at!

The issue is you use the same rotate threshold for when the character is facing right and left, so when you straddle the threshold he flips a lot and its bad UX for the player.
Solution : make the rotate threshold dynamic so each time the player rotates the threshold gets pushed down.
float thresholdAngle = 90.0f;
change angle > 90 || angle < -90 to
if (angle > thresholdAngle || angle < -1.0f * thresholdAngle)
Then add in
if (rotate == true)
{
transform.Rotate(0f, 180f, 0f);
thresholdAngle = 110.0f;
}
else
{
transform.Rotate(0f, 0f, 0f);
thresholdAngle = 80.0f;
}
I'm not sure which way your character faces first so you may have to swap the thresholdAngle = 110.0f with the threshold = 80.0f;

How to detect if player is moving Left/Right/Back/Forward

My player can only move along straight horizontal and vertical lines. I want to detect whether they are moving left, right, back, or forward at any given point in time. They can rotate any way they like in the game.
I've tried detecting this when users press the arrows keys and then checking if the current player position along the X or Y (z transform) planes is different than it was before. That didn't seem to work.
I also tried using this code from Unity answers where a similar question was asked but it isn't working for me:
float dot = Vector3.Dot(transform.forward, Vector3.forward);
if(dot > 0.9) // going forward direction
else if (dot < - 0.9) // going opposite to forward direction
else{
Vector3 cross = Vector3.Cross(transform.forward, Vector3.forward);
// This could be the other way around...never remember which order
if(cross.y < 0) // going right
else // going left
}

The best way would be to check the velocity if your Character gets moved by Physics. If your Character moves with something where velocity does not fulfill the job, then you would save the last position and check it with the new one like your first idea was.
Velocity
So like I said when your Character moves with Physics you could check the direction like this:
public RigidBody rb; // Add the rigidbody of your Player to your script
void Update() {
// What ever your code is here
Vector3 vel = transform.rotation * rb.velocity;
if(vel.z > 0) {
// forward
} else if(vel.z < 0) {
// backwards
}
if(vel.x > 0) {
// right
} else if(vel.x < 0) {
// left
}
}
Position
You can also check the movement by position. For this you need to compare not only old Pos and new Pos but also old Rotation and new Rotation.
What I could think of is:
(Not tested)
Vector3 oldPos;
Quaternion oldRot;
Update() {
Vector3 movement = oldRot * (transform.position - oldPos));
if(movement.z > 0) {
// forward
} else if(movement.z < 0) {
// backwards
}
if(movement.x > 0) {
// right
} else if(movement.x < 0) {
// left
}
oldPos = transform.position;
oldRot = transform.rotation;
}

Move 2D object at constant speed and turn towards touch point

I've been trying for a while to get a 2D player to work kind of like a bullet that is always moving forward (forward being in this case the local X axis for the GameObject, as that's the way that the character is facing) and only changes direction when you touch a point on the screen, in which case it should smoothly start turning towards that point.
One problem I have is that I can't manage to keep the character moving smoothly at a constant speed in the last direction it was facing before, and the other problem that I'm finding is that the character is turning around the wrong axis and instead of rotating based on the Z axis, it's always rotating on the Y axis, which makes the sprite become invisible to the camera.
Here's the code that I have right now:
Vector3 lastTouchPoint;
private void Start()
{
lastTouchPoint = transform.position;
}
void Update()
{
if (Input.touchCount > 0)
{
// The screen has been touched so store the touch
Touch touch = Input.GetTouch(0);
if (touch.phase == TouchPhase.Stationary || touch.phase == TouchPhase.Moved)
{
// If the finger is on the screen, move the object smoothly to the touch position
lastTouchPoint = Camera.main.ScreenToWorldPoint(new Vector3(touch.position.x, touch.position.y, 10));
}
}
transform.position = Vector3.Lerp(transform.position, lastTouchPoint, Time.deltaTime);
//Rotate towards point
Vector3 targetDir = lastTouchPoint - transform.position;
transform.LookAt(lastTouchPoint);
}
Thanks in advance!

keep the character moving smoothly at a constant speed
You probably didn't understand what Lerp actually is: This interpolates between the two positions on the given factor where 0 means fully the first position, 1 means fully the last position and e.g. 0.5f would mean in the center between both positions.
This results in faster speeds if the positions are further apart and becomes slower and slower the smaller the distance between both positions becomes. In some cases especially with a factor that small as in your case the object might even never actually reach the target position.
Using this with a dynamic factor of Time.deltaTime makes no sense as this value changes every frame and jitters somewhere around 0,017 (assumin 60 FPS).
You could rather use Vector3.MoveTowards with a fixed constant speed
// set via the Inspector
public float speedInUnitsPerSecond = 1;
...
transform.position = Vector3.MoveTowards(transform.position, lastTouchPoint, Time.deltaTime * speedInUnitsPerSecond);
if you want to keep moving but stop once the touched position is reached.
If you rather wanted to continue moving in the according direction no matter what you could rather store the direction instead of a position and use a straight forward Transform.Translate
// set via the Inspector
public float speedInUnitsPerSecond = 1;
private Vector2 lastDirection;
privtae void Update()
{
...
// If the finger is on the screen, move the object smoothly to the touch position
var touchPosition = Camera.main.ScreenToWorldPoint(new Vector3(touch.position.x, touch.position.y, 10));
lastDirection = (touchPosition - transform.position).normalized;
...
// move with constant speed in the last direction
transform.Translate(lastDirection * Time.deltaTime * speedInUnitsPerSecond);
...
}
the character is turning around the wrong axis and instead of rotating based on the Z axis, it's always rotating on the Y axis
Note that Transform.LookAt has an optional second parameterworldUp which by default is Vector3.up so a rotation around the global Y axis!
Since you rather want a rotation around the Z axis you should pass
transform.LookAt(lastTouchPoint, Vector3.forward);
I don't know your setup ofcourse but also note that
LookAt
Rotates the transform so the forward vector points at worldPosition.
As you describe it it is also possible that you don't want the objects forward vector to point towards the target position but actually rather the objects right (X) vector!
You can do this by rather simply directly setting the transform.right like e.g.
transform.right = (lastTouchPoint - transform.position).normalized;
or
transform.right = lastDirection;
Btw it would actually be enough to set this rotation only once, namely the moment it changes so in
if (touch.phase == TouchPhase.Stationary || touch.phase == TouchPhase.Moved)
{
// If the finger is on the screen, move the object smoothly to the touch position
lastTouchPoint = Camera.main.ScreenToWorldPoint(new Vector3(touch.position.x, touch.position.y, 10));
transform.right = (lastTouchPoint - transform.position).normalized;
}
or
if (touch.phase == TouchPhase.Stationary || touch.phase == TouchPhase.Moved)
{
// If the finger is on the screen, move the object smoothly to the touch position
var touchPosition = Camera.main.ScreenToWorldPoint(new Vector3(touch.position.x, touch.position.y, 10));
lastDirection = (touchPosition - transform.position).normalized;
transform.right = lastDirection;
}

I ended up finding the answer to my own problem using code to rotate smoothly from another post. Here's the code:
Vector3 lastTouchPoint;
Vector3 direction;
Vector3 vectorToTarget;
//Character controller variables
public float moveSpeed = 5f;
public float angularSpeed = 3f;
private void Start()
{
lastTouchPoint = transform.position;
}
void Update()
{
if (Input.touchCount > 0)
{
// The screen has been touched so store the touch
Touch touch = Input.GetTouch(0);
if (touch.phase == TouchPhase.Began)
{
// If the finger is on the screen, move the object smoothly to the touch position
lastTouchPoint = Camera.main.ScreenToWorldPoint(new Vector3(touch.position.x, touch.position.y, 10));
direction = lastTouchPoint - transform.position;
vectorToTarget = lastTouchPoint - transform.position;
}
}
transform.position += direction.normalized * moveSpeed * Time.deltaTime;
float angle = Mathf.Atan2(vectorToTarget.y, vectorToTarget.x) * Mathf.Rad2Deg;
Quaternion q = Quaternion.AngleAxis(angle, Vector3.forward);
transform.rotation = Quaternion.Slerp(transform.rotation, q, Time.deltaTime * angularSpeed);
}

Move character in unity

I am new to unity and was wandering how to move a character so that it will stop when it hits a wall.
Currently i have used code like this:
Vector3 pos = transform.position;
if(Input.GetKey("a")) pos.x -= 1;
if(Input.GetKey("d")) pos.x += 1;
transform.position = pos;
However with this the character will move through walls.
I have added a rigidbody component to the char.
EDIT: Yes they do have a box collider on them, and the char does actually start to "bounce" when they collide, but the char goes right through the wall.

You need to let the Physics engine do the moving for you, so don't set the transform.position yourself. Set the rigidbody.velocity instead.
int xVelocity = 0;
if(Input.GetKey("a"))
{
xVelocity = -1;
}
else if(Input.GetKey("d"))
{
xVelocity = 1;
}
rigidbody.velocity = new Vector3(xVelocity, 0, 0);