I'm starting with Unity 3D and I want to make a simple game where you move a marble through a maze by tilting the device.
For that I need to know in what the direction the phone is tilted (where to move the ball) and how much (how fast to move it). This bubble level from iOS7 does something similar, the number rotates to show the direction you are tilting the device and the value represents how much the phone is tilted:
I've been experimenting with Input.gyro.attitude.eulerAngles but I'm not sure how to turn it into the values I need, also I'm not sure if gyro.attitude is the best solution to get responsive controls.
How can I get the direction and tilt of the device?
Unity3D documentation has a solution using Input.accelaration however I'm not sure whether it's as reliable as Input.gyro.
http://docs.unity3d.com/ScriptReference/Input-acceleration.html
This is what I'm trying now:
private Gyroscope gyro;
void Start () {
gyro = Input.gyro; // Store the reference for Gyroscope sensor
gyro.enabled = true; //Enable the Gyroscope sensor
}
void Update () {
// Gyroscope
Vector3 vec = gyro.attitude * Vector3.forward;
print (vec);
// Option 2
print(Input.accelaration);
}
You should be able to do it like this (in this case, taking the XZ plane projection of the quaternion = change the Vector3 in the second line to pick the plane you want);
// where q is the Quaternion from the gyro
Matrix4x4 quatMatrix = Matrix4x4.TRS(Vector3.zero, q, Vector3.one);
Matrix4x4 scaleMatrix = Matrix4x4.TRS(Vector3.zero, Quaternion.identity, new Vector3(1, 0, 1));
Matrix4x4 scaled_matrix = scaleMatrix * quatMatrix;
OutVector = scaled_matrix.MultiplyVector(Vector3.forward).normalized;
That should give you a 3-d vector that has only X and Z components, easy to turn into a 2-d vector.
Related
I'm learning unity and c#, and want to make my movement to be camera relative movement instead of world relative movement. How do I do that?
I'm learning unity and c#, my unity version is 2018.3.12f1. I would be happy for help.
just to let know, instead of moving the cam I'm rotating the player.
void Update()
{
float AxisY = Player.transform.eulerAngles.y;
/* Movement starts here */
Vector3 Movement = new Vector3 (Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
if (Input.GetKey(KeyCode.LeftShift) || Input.GetKey(KeyCode.RightShift)) { //running code
Player.transform.position += Movement * running_speed * Time.deltaTime;
} else {
Player.transform.position += Movement * speed * Time.deltaTime;
}
/*Movement ends here */
/* Rotation controller starts here */
Quaternion target = Quaternion.Euler(Player.transform.eulerAngles.x, Player.transform.eulerAngles.y, Player.transform.eulerAngles.z);
/*if (Player.transform.eulerAngles.x != 0 || Player.transform.eulerAngles.z != 0 || Player.transform.eulerAngles.y != 0) {
Player.transform.rotation = Quaternion.Euler(0,0,0);
}*/
if (Input.GetKey(KeyCode.E))
{
Debug.Log("E got pressed");
//float AxisYPositive = Player.transform.eulerAngles.y;
AxisY = AxisY+1;
Player.transform.rotation = Quaternion.Euler(0, AxisY, 0);
} else if (Input.GetKey(KeyCode.Q))
{
Debug.Log("Q got pressed");
//float AxisYNegetive = Player.transform.eulerAngles.y;
AxisY=AxisY-1;
Player.transform.rotation = Quaternion.Euler(0, AxisY, 0);
}
}
}
The player's movement is world relative, how to make the movement camera relative?
If you want to make the movements relative to the gameObject, call the method Transform.Rotate() on the transform of the gameObject you want to rotate rather than modifying its Quaternion directly. Just make sure the final argument is set to Space.Self.
if (Input.GetKey(KeyCode.E))
{
Debug.Log("E got pressed");
//float AxisYPositive = Player.transform.eulerAngles.y;
AxisY = AxisY+1;
Player.transform.Rotate(Quaternion.Euler(0, AxisY, 0), Space.Self);
}
In general you don't want to directly mess with objects transform.rotation, at least not unless you at least somewhat understand quaternions (I don't!).
I can see a few issues with your code, but the common thread seems to be that you don't really understand how transforms work. Specifically, you might want to look into World/Local space.
The usual way to control a player goes roughly like this:
void DoMovement(Transform player)
{
//If you move first your controls might feel 'drifty', especially at low FPS.
Turn(player);
Move(player);
}
void Turn(Transform player)
{
float yaw = Input.GetAxis("Yaw") * time.deltaTime; //Aka turn left/right
player.Rotate(0, yaw, 0, Space.Self);
// Space.Self is the default value, but I put it here for clarity.
//That means the player will rotate relative to themselves,
//...instead of relative to the world-axis, like in your code.
}
You didn't ask about movement, but as-is your character will always move relative to the world. The below should make it move relative to the camera.
Transform _cameraTransform; //Assumes this is set druing Start()
void Move(Transform player)
{
var forwardMove = _cameraTransform.Forward; //Get whatever direction is 'forward' for camera
forwardMove.Y = 0; //Don't want movement up and down.
forwardMove = forwardMove.normalized; //Normalize sets the 'power' of the vector to 1.
//If you set Y to 0 and don't normalize you'll go slower when camera looks down
//...than when camera is flat along the plane
player.position += forwardMove * Input.GetAxis("Vertical") * time.deltaTime;
//Here you could do the same for strafe/side to side movement.
//Would be same as above, but using the transform.right and Horizontal axis
}
Now, I'm making some assumptions here since you haven't specified what kind of game it is and what kind of controls you want. I'm assuming you have a character running around on a mostly flat plane (no aircraft/spaceship controls), and that the camera is attached to the player. This might not not actually be the case.
In any case I advice you to check out the tutorials, especially the Roll-a-Ball tutorial which I have found is good for beginners to get a grasp on basic players controls that are not just world-relative. The other tutorials, too, are pretty good if you think they're interesting.
Aside from the official Unity tuts a ton of decent to amazing tutorials out there, including video tutorials, so for something like this you could just search for <game type> tutorial and pick whatever seems good to you. While getting started I advice you to avoid the shortest videos, as you will likely benefit greatly from explanation that only fits in longer videos. Of course, that doesn't mean you should pick the longest videos either.
In case someone needs to move an object and don't care about colliders, you can use transform.Translate and assign to his second parameter relativeTo your camera (or any transform) to automatically calculate the translation relative to the object assigned.
I'm trying to implement centripetal force in a programming language.
I saw some videos teaching the theory. But I dont know how to apply that in a programming language.
If I understand I have to apply centripetal force ac = v²/r to the velocity vector. But I dont know exactly how to proceed.
I have two game objects, one depicting Earth, other depicting Moon. What I wanted is to translate the moon around earth and using a button to "cut/cancel" the centripetal force in order to the moon get out to the earth's orbit.
I have no clue how to start that.
All I know is to rotate like this:
velocity.x = Mathf.Cos(Time.time) * earth_moon_radius;
velocity.z = Mathf.Sin(Time.time) * earth_moon_radius;
moon.transform.position = velocity;
But how to apply centripetal force as described above?
If you just want to have the moon rotating around earth and some trigger to release the moon, it's easier to use rotation around a center instead of forces. Given the following GameObject hierarchy:
Center (MoonRotator attached)
-- Moon
-- Earth
public class MoonRotator : MonoBehaviour
{
public bool cancelCentripetalForce = false;
public Vector3 angularVelocity = new Vector3 (0f, 0f, 100f);
public GameObject moon;
void Update () {
if (cancelCentripetalForce) {
Vector3 radius = moon.transform.position - transform.position;
Vector3 angularVelocityRadians = Mathf.Deg2Rad * angularVelocity;
moon.rigidbody.velocity = Vector3.Cross (angularVelocityRadians, radius);
moon.transform.parent = null;
Destroy (this);
} else {
Vector3 rot = transform.rotation.eulerAngles + angularVelocity * Time.deltaTime;
transform.rotation = Quaternion.Euler (rot);
}
}
}
If cancelCentripetalForce is set true Moon stops travelling around earth but proceeds with its current tangential velocity. This is given as:
v = ω × r
Earth has localPosition (0, 0, 0) and Moon is in this example located in the x-y plane rotating around the z axis.
If you want to cancel the force, add an opposing force vector that is based on your object's linear velocity and current direction.
So I have an object pointing straight along the Z axis. The object's 'forward' vector is 0, 0, 1. Do 1 - Math.abs(forward.x), same for y and z to get 1, 1, 0 when you're pointing forward along the Z axis. You want the direction you're pointing in to be 0'd so that the inertia from that direction is not damped in any way. Now you can apply a cancellation force in any direction that you are NOT pointed in.
This means that if your object is moving in any direction in world space that it's not facing in you can easily apply a cancellation force that is multiplied by the object's linear velocity to get circular motion that uses forces instead of directly setting velocity.
Another way you can do it is solve for V by manually setting it, then find radius using V=RW. You should know V and R or W. Now you can find the force necessary to keep the orbit stable around a point, rather than adding inertia from every frame.
I am pretty new to unity but i have a basic FPS game made, when holding a gun, i would like to make it so when your player turns, the item in hands rotates to show turning. For example, when playing call of duty, the gun rotates when you rotate your character. This is the code i have but it is not working
void Update(){
this.rotateEquppedOnTurn();
}
private void rotateEquppedOnTurn(){
if(this.equippedItem != null){
InteractEquppableItem equip = this.equippedItem.gameObject.GetComponent<Interaction>() as InteractEquppableItem;
if(equip.rotatesWhenTurn){
float rotX = Input.GetAxis("Mouse X");
float rotY = Input.GetAxis("Mouse Y");
Quaternion tempRot = new Quaternion();
Quaternion tempCam = GameObject.Find("PlayerCamera").transform.rotation;
tempRot.x = tempCam.x + rotX;
tempRot.y = tempCam.y + rotY;
tempRot.z = tempCam.z;
this.equippedItem.gameObject.transform.rotation = tempRot;
}
}
}
when turning the character with this code, the gun just rotates in a weird way, its not quite what i expected from the rotation script
Quaternions are not vectors.
I suggest you start by watching the vector tutorial on Unity's web site.
The last bit of the tutorial goes over what cross products are and why you would use them - specifically, you can use them to obtain a relative axis around which you may want to rotate something.
Don't directly assign rotation like this.
this.equippedItem.gameObject.transform.rotation = tempRot;
instead of that use something like this
this.equippedItem.gameObject.transform.Rotate(new Vector3(x,y,z));
you can derive x,y,z using mouse motion
I'm working on a 3D XNA project, and I've been thinking about this problem for like 2 weeks.
So I just decided to ask you.
Basically I have a flat plane and i want to project the mouse position to that plane, but how?
I tried many ways to do it, calculated angles...
But i figured out, that the distance must effect on the X position, maybe some math is needed what I've never heard before.
I did some code few years ago which returns the position as Vector3(x,y,z), given mouse state:
private Vector3 FindWhereClicked(MouseState ms)
{
Vector3 nearScreenPoint = new Vector3(ms.X, ms.Y, 0);
Vector3 farScreenPoint = new Vector3(ms.X, ms.Y, 1);
Vector3 nearWorldPoint = device.Viewport.Unproject(nearScreenPoint, cam.projectionMatrix, cam.viewMatrix, Matrix.Identity);
Vector3 farWorldPoint = device.Viewport.Unproject(farScreenPoint, cam.projectionMatrix, cam.viewMatrix, Matrix.Identity);
Vector3 direction = farWorldPoint - nearWorldPoint;
float zFactor = -nearWorldPoint.Y / direction.Y;
Vector3 zeroWorldPoint = nearWorldPoint + direction * zFactor;
return zeroWorldPoint;
}
device is an instance of GraphicsDevice.
Hope it works for you.
I thought I understood matrix math well enough, but apparently I'm clueless
Here's the setup:
I have an object at [0,0,0] in world space. I have a camera class controlled by mouse movements to rotate and zoom around the object such that it always looks at it. Here is how I calculate my viewMatrix from the camera:
public Matrix viewMatrix {
get {
return
Matrix.CreateFromAxisAngle(Vector3.Up, rotAngle)
* Matrix.CreateFromAxisAngle(Vector3.Left, pitchAngle)
* Matrix.CreateTranslation(0, 0, distance)
;
}
}
I need to be able to get the position of the camera in world space so I can get its distance from the box--particularly its distance from each face of the box. How can I get the camera's xyz position in world space coords?
I've tried:
// all of these only return [0, 0, distance];
Vector3 pos = Vector3.Transform(Vector3.Zero, viewMatrix);
Vector3 pos = viewMatrix.Translation;
Vector3 pos = new Vector3(viewMatrix.M41, viewMatrix.M42, viewMatrix.M43);
It seems like the rotation information is being lost somehow. The strange thing is that the viewMatrix code works perfectly for positioning the camera!
or to simplify slightly:
Vector3 pos = Matrix.Invert(view).Translation;
Once again, I figure out the problem within seconds of posting the question:
I needed to invert the view matrix. The rotation info was being lost because it plays no part in the distance calculation until the view matrix is inverted. The rotation was at the wrong "end" of the transformation.
Vector3 pos = Vector3.Transform(Vector3.Zero, Matrix.Invert(viewMatrix));