Unity - 对 object 应用两个局部旋转（尝试将 controller 操纵杆的旋转重新创建为 3D 网格操纵杆）

Question

I would like to recreate one on one the rotation of the real life controller joystick (ie 360 controller) into a 3D joystick mesh (that resembles the 360 controller one).

I thought about doing it by rotating the joystick in the X axis according to the magnitude of the input (mapping it to a min and max rotation in the X axis). And then figure the angle of the input and apply it to the Y axis of the 3D joystick.

This is the code I have, the joystick tilts properly in the X axis but the rotation in the Y axis doesn't work:

    public void SetStickRotation(Vector2 stickInput)
{
    float magnitude = stickInput.magnitude;

    // This function converts the magnitude to a range between the min and max rotation I want to apply to the 3D stick in the X axis
    float rotationX = Utils.ConvertRange(0.0f, 1.0f, m_StickRotationMinX, m_StickRotationMaxX, magnitude);
    
    float angle = Mathf.Atan2(stickInput.x, stickInput.y);
    
    // I try to apply both rotations to the 3D model
    m_Stick.localEulerAngles = new Vector3(rotationX, angle, 0.0f);
}

I am not sure why is not working or even if I am doing it the right way (ie perhaps there is a more optimal way to achieve it).

Many thanks for your input.

Answer 1

I would recommend rotating it by an amount determined by the magnitude around a single axis determined by the direction. This will avoid the joystick spinning around, which would be especially noticeable in cases of asymmetric joysticks such as pilots joysticks:

Explanation in comments:

public void SetStickRotation(Vector2 stickInput)
{
    /////////////////////////////////////////
    // CONSTANTS (consider making a field) //
    /////////////////////////////////////////

    float maxRotation = 35f; // can rotate 35 degrees from neutral position (up)

    ///////////
    // LOGIC //
    ///////////

    // Convert input to x/z plane
    Vector3 stickInput3 = new Vector3(stickInput.x, 0f, stickInput.y);

    // determine axis of rotation to produce that direction
    Vector3 axisOfRotation = Vector3.Cross(Vector3.up, stickInput3);

    // determine angle of rotation
    float angleOfRotation = maxRotation * Mathf.Min(1f, stickInput.magnitude);

    // apply that rotation to the joystick as a local rotation
    transform.localRotation = Quaternion.AngleAxis(angleOfRotation, axisOfRotation);
}

This will work for joysticks where:

1. the direction from its axle to its end is the local up direction,
2. it should have zero (identity) rotation on neutral input, and
3. stickInput with y=0 should rotate the knob around the stick's forward/back axis, and stickInput with x=0 should rotate the knob around the stick's left/right axis.

Answer 2

Figure out the problem, atan2 returns the angle in radiants, however the code assumes it is euler degrees, as soon as I did the conversion it worked well. I put the code here if anyone is interested (not the change in the atan2 function):

public void SetStickRotation(Vector2 stickInput)
{
    float magnitude = stickInput.magnitude;

    // This function converts the magnitude to a range between the min and max rotation I want to apply to the 3D stick in the X axis
    float rotationX = Utils.ConvertRange(0.0f, 1.0f, m_StickRotationMinX, m_StickRotationMaxX, magnitude);
    
    float angle = Mathf.Atan2(direction.x, direction.y) * Mathf.Rad2Deg;
    
    // Apply both rotations to the 3D model
    m_Stick.localEulerAngles = new Vector3(rotationX, angle, 0.0f);
}