I'm trying to create a system in VR in which an object rotation follows the rotation of the player's hand. Unfortunately, when the hand rotates at a high angle, the rotated object flips in a strange way as if it had a problem with the rotation change from 360 degrees to 0. I tried many ways to solve this problem, but each one that worked did not allow me to change "sensitivity" on the basis of:
1 - target is rotating 1: 1 ratio with hand
2 - target is rotating twice as much as hand
etc.
// In FixedUpdate
Quaternion deltaRotation = Quaternion.Inverse(target.rotation) * hand.rotation;
deltaRotation.ToAngleAxis(out float angle, out Vector3 axis);
target.rotation *= Quaternion.AngleAxis(angle * sensitivity, axis);
Any help would be appreciated!
So the problem is in
Quaternion deltaRotation = Quaternion.Inverse(target.rotation) * hand.rotation;
if the sensitivity is != 1 these objects rotations get desynchronized so the deltaRotation will not give you the value you expect. You probably wanted to check how much hand rotated since last frame, like that:
Quaternion _lastFrameRotation;
void Awake()
{
_lastFrameRotation = transform.rotation;
}
private void FixedUpdate()
{
Quaternion deltaRotation = Quaternion.Inverse(_lastFrameRotation) * transform.rotation;
deltaRotation.ToAngleAxis( out float angle, out Vector3 axis );
target.rotation *= Quaternion.AngleAxis( angle * sensitivity, axis );
_lastFrameRotation = transform.rotation;
}
Related
I want to rotate the object around y axis 90　degree.
What I want to do is very simple
getPosition(Quaternion rotation)
rotation.y = rotation.y + 90.0f;
_rotateTarget.rotation = rotation;
it shows error.
I googled around and found I need to understand Quaternion
However I can't find first clue to rotate object simply 90 degree.
Is there any help??
If you want to rotate an object smoothly to a target rotation you can use Quaternion.Slerp. The following script lets you set the x, y and z rotation.
[Header("Settings")]
public Vector3 targetRotation;
public float rotationSpeed = 5;
private Quaternion currentTargetRotation;
// Start is called before the first frame update
void Update()
{
if (currentTargetRotation.eulerAngles != targetRotation)
currentTargetRotation.eulerAngles = targetRotation;
transform.rotation = Quaternion.Slerp(transform.rotation, currentTargetRotation, rotationSpeed * Time.deltaTime);
}
A Quaternion has not three but rather four components x, y, z and w! And they all move in the range -1 to 1.
=> Never touch the individual components of a Quaternion except you really know exactly what you are doing!
For rotating the object on the global Y-axis you rather want to use e.g. Quaternion.Euler as the name suggests generates a Quaternion rotation from the given Euler space angles.
Returns a rotation that rotates z degrees around the z axis, x degrees around the x axis, and y degrees around the y axis; applied in that order.
rotation *= Quaternion.Euler(0, 90, 0);
// Or also
//rotation *= Quaternion.Euler(Vector3.up * 90);
_rotateTarget.rotation = rotation;
Or if you want to rotate in any given axis you can also use Quaternion.AngleAxis
rotation *= Quaternion.AngleAxis(90, Vector3.up);
_rotateTarget.rotation = rotation;
And then you always combine two Quaternion using the multiplication * operator.
var final = rotA * rotB;
basically means first apply the rotation rotA then starting from there additionally apply the rotB.
rotation *= rotB;
is just a shorthand for writing
rotation = rotation * rotB;
In the GIF above I am moving the plane with the mouse up and down. Watch how when I rotate the plane on its Z axis the plane still moves up and down even if the plane is side ways now. That is my bug. Why is this happening? What is wrong with my code? I think I am using the global axis and not the gameobjects axis. How do I fix this please.
x += Input.GetAxis("Mouse X") * xMouseSpeed * 0.02f;
y -= Input.GetAxis("Mouse Y") * yMouseSpeed * 0.02f;
if (Input.GetKey(KeyCode.Q))
{
rotZ += Time.deltaTime * 50f;
}
if (Input.GetKey(KeyCode.E))
{
rotZ -= Time.deltaTime * 50f;
}
Quaternion rotation = Quaternion.Euler(y, x, rotZ);
planeBodyToMove.localRotation = rotation;
What happens is that the localRotation is just the rotation in relation to the parent object.
The rotation of the transform relative to the transform rotation of the parent.
Or in other words: The localRotation is not local to the object itself but rather a rotation in the local space of the parent (or Unity world space if there is no parent). It does not mean that you rotate around your local Y axis necessarily. It applies the rotations in the parent's local space in the order Z, X, Y .. that is why sometimes you actually don't note the difference until you rotate Y!
As you can see here the same thing happens also without your code by just doing the rotation via the Inspector
Or to demonstrate it a bit better lets see what happens if we rotate it the way you actually want it to rotate:
as you can see as soon as one axis already is rotated, changing another axis now changes all three rotation values.
Solution
So how to solve this?
Usually I'm to lazy to do Quaternion calculations myself → I let the Transform do this for me ^^
Instead of storing the expected rotation in fields and apply it everytime by converting it into a Quaternion you can directly use Transform.Rotate which rotates the object actually using its own local axis:
// Just a question of taste but I would prefer to have
// values that belong together in one single struct instead of multiple fields
public Vector2 mouseSensitivity = Vector3.one;
private void Update()
{
var xDif = Input.GetAxis("Mouse X") * mouseSensitivity.x;
var yDif = - Input.GetAxis("Mouse Y") * mouseSensitivity.y;
var zDif = 0f;
if (Input.GetKey(KeyCode.Q))
{
zDif= Time.deltaTime * 50f;
}
else if (Input.GetKey(KeyCode.E))
{
zDif= -Time.deltaTime * 50f;
}
// Wihout the optional space parameter uses local space by default
planeBodyToMove.Rotate(new Vector3(xDif, yDif, zDif));
}
As you can see now each rotation is actually applied in the plane's local axis:
I am trying to archive without success a z-axis rotation movement around a moving object keeping always "looking at front". So it should looks like this:
The closest I got was with:
transform.RotateAround(targetPosition, Vector3.forward, moveSpeed);
But it does not keeps looking "at front".
Could someone give me a hand with this?
Thank you in advance.
Best regards.
If your object ("Lightning Bolt") has no world rotation, i.e. aligned with the world axis as your example image seems to suggest, then the easiest is to simply set the world rotation to the Quaternion Identity:
transform.rotation = Quaternion.identity;
Note that the image wont rotate if its parent object rotates. It will essentially "Billboard" your lightning object. If you want to your lightning bolt to be aligned with a parent object, then try something like:
transform.rotation = transform.parent.rotation;
Fitst store the current rotation, then rotate around point, lastly apply the previous rotation.
var rot = transform.rotation;
transform.RotateAround(targetPosition, Vector3.forward, moveSpeed);
transform.rotation = rot;
A simple solution would just manipulate actual coordinates and ignore rotation ^^ If an object moves and you want it to keep rotating around it, just make it a child object.
This is a 3d solution where we rotate around Y:
void Start() { angle = 0.0f }
void Update() {
angle += speed * Time.deltaTime; //Your starting angle that will be modified every frame
CheckAngle(ref angle);
float x = Mathf.Cos(angle * Mathf.Deg2Rad) * Radius;
float z = Mathf.Sin(angle * Mathf.Deg2Rad) * Radius;
}
static void CheckAngle(ref float Angle) //It should probably return a value by it's name here tho not ref, not sure which is the correct way of doing this
{
if (Angle > 360) //You don't want your angle to go past the boundaries of an INT
Angle = 0;
}
I'm making a topdown game with the camera at 40 degree angle. What I want to do is when i click an gameobject, It will move the camera and position the object at the left side from the center of the camera view regardless of its rotation. So that I can place a menu at the right side. How do I get the offset of the angled camera so that the object is in the middle left side of the camera view?
Right now i use lerp but it overshoots the target because of the cameras angle. Sorry for the noob question I'm new to unity3d.
transform.position = Vector3.Lerp(transform.position, new Vector3(target.transform.position.x, transform.position.y, target.transform.position.z), 0.1f);
First of all you should start by finding point that your camera will move/lerp to.
In your case in can be simplified to 2D-Space:
It shouldnt be tough to find that one.
Use transform.forward of camera to get vector (Vector3 cameraDir) of direction your camera is looking at
Rotate by horizontal fov / 4 around y axis:
Vector3 cameraDirRotated = Quaternion.AngleAxis(hFov/4f, Vector3.up) * cameraDir;
-cameraDirRotated will be vector from Cube To point P you're looking for, u can also scale it:
Vector3 PtoMoveTo = cube.transform.position - cameraDirRotated.normalized * 5f;
Full:
Vector3 FindCameraTarget(Transform targetObj, float hFov)
{
Vector3 cameraDir = transform.forward;
Vector3 cameraDirRotated = Quaternion.AngleAxis(hFov / 4f, Vector3.up) * cameraDir;
Vector3 target = targetObj.transform.position - cameraDirRotated.normalized * 5f;
return target;
}
Then:
transform.position = Vector3.Lerp(transform.position, FindCameraTarget(target, 90f) , 2f * Time.deltaTime);
For performance u can save that target vector once if Cube is not moving. Search web how to precisely count horizontal fov. Multiply speed by Time.timeDelta if u lerp in Update().
I am making a game where there is a tank that shoots some objects.
I want to rotate the gun of the tank in between the llimits of -90 to 90 degrees in "X".
I used transform.rotate but it rotates the gun with some float values (0.0 to 1.0) and the rotation I see on the inspector is something different. How to solve this issue?
Use below code from Mathf class
static float Clamp(float value, float min, float max);
e.g.
var angle = Mathf.Clamp(angle, 90, 270);
Quaternion target = Quaternion.Euler(0, 0, angle); // any value as you see fit
transform.rotation = target;
I found the answer I used eularAngles to limit the rotations as follows
if((gun.eulerAngles.z<90)||(gun.eulerAngles.z>270))
{
gun.Rotate(0,0,turnAngle);
}