I have a ball object in Unity 2D, this ball spawns at random positions on the screen and I want it to move in a 'straight-line depending on its direction e.g. if it's from the left it goes to the right or if it's from the top it goes to the bottom. I'm not sure if I should use transform.position/addforce/velocity to accomplish this and what direction I should use.
The following are what I have tried so far (I've tried using all directions)
ballRigidBody.AddForce(transform.up * speed);
ballRigidBody.velocity = Vector2.up * speed;
transform.position+=Vector2.up;
In Unity3D transform.forward is the go to variable when you want to move forward.
In Unity2D transform.right is the standard.
You can move your ball to its right with this code:
void Update()
{
GetComponent<Rigidbody2D>().velocity = transform.right * speed;
}
If you run this code the ball will always move into the direction of the red arrow.
You can see the arrows by selecting the move tool on the top left and then clicking on your ball inside the editor.
If you want to have your ball to always follow the green arrow you have to use transform.up.
transform.right and transform.up are both used relative to your object.
That means by changing the z rotation of your object you can modify the direction it should go in.
You can try out the following code to see your ball move to its right and rotate slowly on its z axis. This will cause the ball to move in a circle since it is still following the red arrow.
void Update()
{
GetComponent<Rigidbody2D>().velocity = transform.right * speed;
float speedRotate = 100;
transform.Rotate(Vector3.forward * speedRotate * Time.deltaTime);
}
When you always want to move an object to the right, no matter the rotation, you use Vector3.right instead of transform.right.
From your other comments I understand that you want your ball to always face into the direction in the middle of the screen. You can just rotate it to the middle of the screen when it spawns by using this code:
void Start()
{
transform.right = new Vector3(0, 0, 0) - transform.position;
}
This will get the ball to face the 0,0,0 position inside of your world. If 0,0,0 is in the middle of your screen it will face that direction. Otherwise you have to find out which coordinate your middle of your screen has.
I'm not sure what you're asking, but you can do ballRigidbody.velocity = transform.foward*speed, to make it go in the current direction it is facing.
If you want a ball you spawn on the left side of the screen to move to the right only, then set velocity like rb.velocity = Vector3.right * speed, and so on with each direction.
In this case, you should first check which position the ball spawned at (Top, Bottom, Left, Right), then from that decide the movement direction. If the ball spawns at the bottom, the direction to go up should be Vector3.up for example.
After you get the force, you can use rigidBody.AddForce(direction * speed); to move the ball.
Related
I'm trying to make the camera rotate around an object according to the movement of the mouse, and this is what I've come up with:
void Start()
{
direction = new Vector3(1f,0f,0);
direction.Normalize();
Debug.Log(direction);
mousePosCurr = Input.mousePosition;
}
void Update()
{
mousePosPrev = mousePosCurr;
mousePosCurr = Input.mousePosition;
mouseVector = (mousePosCurr - mousePosPrev);
mouseVector = mouseVector * sensitivity;
direction = Quaternion.Euler(mouseVector.y, mouseVector.x, 0) * direction;
direction.Normalize();
Debug.Log(direction);
this.transform.position = (target.position + tOffset + (direction * distance));
transform.LookAt(target.position + tOffset, Vector3.up);
}
Now, I'm sure that there are at least a million problems with this code, however the main one I'm facing right now is that the x rotation does not work correctly, unless the y rotation is in a specific direction.
What's happening is basically that the more I rotate in the y axis the more "inprecise" the x movement becomes. So for example, when the camera is south of the object I'm rotating it around, the x rotation works exactly as it should, you move the mouse up, and the camera points up and viceversa, but when it's west of it the movement of the mouse required for the vertical rotation is no longer vertical, but diagonal, and when it's north of the object the movement is inverted: moving the mouse up makes the camera point down and viceversa.
This seems most likely caused by the fact that regardless of the horizontal rotation of the direction vector, I'm still rotating along the x axis in the same direction, as if the camera was south of the object.
However, even having (hopefully) identified the problem, I'm still clueless as to how to solve it, so I'm asking for help here.
Note: I just noticed that I probably used the term "rotation" wrong in this post. When I write "rotation of the camera", I'm actually referring to the rotation of the "direction" vector.
alright so I am not the best in Unity so this might be completely useless but when I try to rotate my camera around an object I create an empty game Object and make the camera a child of it, like this
so that I can just just rotate the Game Object to rotate the camera around a fixed point maybe your code will work
This is a school project. I have a big cube which is like a planet. I have a small cube that can move on every side of the cube planet. The player moves forward automatically on its local z axis and I rotate it by 90 or -90 degrees to move left or right- but the player can control it like it's an up-down-left-right movement (made a script so they don't have to rotate the cube with 2 keys). It's like a Tron game so if I press the up key, I can't press down immediately because I leave a trail so I have to press the left or right keys. I have a problem with my camera movement. The camera follows the little cube from above, but I want it to lean a little when the little cube player gets close to the edge of a side so it lets me see the other side - where I'm planning to go.
I have a script where I use the center of the cube planet and the player's center as the direction vector and multiply it with the camera-player distance.
Vector3 direction = (target.position - center.position).normalized;
transform.position = target.position + direction * distance;
Then I point my camera's forward vector to the player cube's direction. I tried two codes but none of them worked perfectly. First I tried to rotate the camera with:
transform.rotation = Quaternion.LookRotation(-direction);
Shown in video. The problem with this is that since I don't tell the program the Up and Right vectors (I think), it sets them for itself to some random numbers so the camera sometimes do its own thing like it does a pirouette.
Next I tried this:
Quaternion rot = Quaternion.FromToRotation(transform.forward, -direction);
transform.Rotate(rot.eulerAngles, Space.World);
Shown in video. It's almost good but as the little cube moves, the camera starts steering slightly in the beginning and it gets worse and worse.
Do you have any ideas how can I make it work? I hope you understand what I would like to achieve. I'm trying to set the camera as to always show that when I press Up, my cube moves upward, when I press Right my cube always goes right etc. and when I reach the edge of my side the camera leans a bit towards the side I'm moving to.
Use dot product to find which orthogonal direction of your cube is closest to the camera's current up.
Vector3 closestToUp;
float greatestDot = 0f;
foreach (Vector3 dir in new Vector3[]{
target.forward, target.right, -target.forward, -target.right})
{
float curDot = Vector3.Dot(dir,transform.up);
if (curDot > greatestDot)
{
greatestDot = curDot;
closestToUp = dir;
}
}
Than, use that direction as the second parameter of Quaternion.LookRotation. This will keep its local up direction as aligned with the cube's "top" as possible given whatever new forward direction:
transform.rotation = Quaternion.LookRotation(-direction, closestToUp);
I have a ai (the red circle) which should shoot at my player (the blue circle).
Currently i'm using a normal Raycast:
Ray ray = new Ray(transform.position, transform.forward);
which gives me the purple Line.
Now, when there is a corner (like on the image), it doesn't hit the player, but it could if it would shoot a bit more to the side.
I've seen a solution for this by adding an angle to that raycast, but this doesn't work for me, because the angle is different if the player is near or far away from the ai.
What i need is:
That the ai shoots a raycast from itself to the side (left & right) of the player, but i don't know how to do that.
Your player certainly has some kind of radius, no?
Just using the distance between the player and the shooting AI, the player's radius and some nice trigonometry, you should be able to generate two rays to test both if the shooting AI sees the player's "right side", as well as his "left side".
Vector3 direction = player.transform.position - shootingAI.transform.position;
float distance = direction.magnitude;
float playerRadius = player.radius;// this is a variable you need to set
float angleToRotate = Mathf.Atan(radius/distance); // trigonometry: tan(angle)=oppositeSideLength/adjacentSideLength
Vector3 rayDirection1 = Quaternion.Euler(0f, -angleToRotate, 0f) * direction;
Vector3 rayDirection2 = Quaternion.Euler(0f, angleToRotate, 0f) * direction;
Using these two rays as directions you should be testing for the "right side", and the "left side"
You can find good answer HERE.
Or maybe use Sphere Raycast and use Contact Point and shot at this point.
I'm new in Unity and I'm working on a simple project but I'm stuck.
So my idea is when the player touches the bottom side of a ball it goes the opposite direction. Pretty much like in real life, if you kick a ball on the bottom side it will go up, but in 2D version.
I tried finding the opposite point of where the player touched the ball and making a vector by subtracting the original point and the opposite point, and then applying force to move the ball but it doesn't work.
void MoveBall()
{
x = mouseClickPosition.x;
y = mouseClickPosition.y;
oppositeClickPosition.x = -x;
oppositeClickPosition.y = -y;
Vector2 direction = oppositeClickPosition - mouseClickPosition;
rb.AddForce(direction * force, ForceMode.Impulse);
}
You have to subtract the mousePosition and the center of the ball.
Vector3 clickedPosition = Camera.main.ScreenToWorldPoint (Input.mousePosition);
Vector3 ballCenter = ballTransform.position;
// If this goes the opposite direction just swap the values.
Vector3 forceDirection = (ballCenter - clickedPosition).normalized;
ballRigidbody.AddForce (forceDirection * strength, ForceMode.Impulse);
This way you find the direction and add the force you want, you can not use the normalized Vector3 if you want to use the distance as a factor too.
And you can catch that event properly on OnMouseDown if the ball has a collider
https://docs.unity3d.com/ScriptReference/MonoBehaviour.OnMouseDown.html
This may be helpful:
https://answers.unity.com/questions/681698/vector-between-two-objects.html
It Explains how to do it in 3D but the idea applies to both.
In your case, instead of oppositeClickPosition you should use the position of the ball:
Vector2 direction = transform.position - mouseClickPosition;
(replace transform.position with the position of the ball if this script is not attatched to the ball)
Hope that helps!
I'm making an arrow, I'm able to make it spin and rotate, but not at the same time. To rotate it (so that the tip points down) I've used this code:
transform.LookAt(transform.position + rigidbody.velocity);
Or this other one:
transform.forward = Vector3.Slerp(transform.forward, rigidbody.velocity.normalized, 10 * Time.deltaTime);
They both works in rotating the arrow toward the terrain.
To spin it I use this code:
transform.Rotate(Vector3.forward, rotatioSpeed * Time.deltaTime);
Unfortunately, if it rotates it doesn't spin, the spin code is placed after the rotation code but the arrow spin only if I comment out the latter.
I'm new to Unity, do you have any idea on how to make it rotate and spin at the same time independently?
A few things you can try
transform.Rotate(transform.forward, rotatioSpeed * Time.deltaTime, Space.World); // <--- transform.forward maybe?
What i would do though is put the arrow inside of a parent empty GameObject that way you can rotate the parent for the direction of the arrow, and then rotate the arrow itself around its own axis independently and that should work for you!