偏心旋转

因此，在storeoffset发生之前，您有一个当前的旋转R。您想计算一个偏移X，使它与旋转R处的局部轴发生偏移，这将产生外观旋转，其中local forward = control-> anchor and local up≈up from R 。

也就是说，

R * X = lookrotation(anchor - control, transform.up)

因此，为了找到X，将方程式的两边乘以左边的inverse（R）：

inverse(R) * R * X = inverse(R) * lookrotation(anchor-control, transform.up)
                 X = inverse(R) * lookrotation(anchor-control, transform.up)

因此，结尾StoreOffset应该是：

rotationOffset = Quaternion.Inverse(transform.rotation) * lookRot;

然后，在UpdateRotationX和带有从〜close-enough〜转换向上的lookRot中，因此通过将两边乘以右边的inverse（X）来求解R：

R * X              = lookrotation(anchor-control, transform.up)
R * X * inverse(X) = lookrotation(anchor-control, transform.up) * inverse(X)
                 R = lookrotation(anchor-control, transform.up) * inverse(X)

因此，结尾UpdateRotation应该是：

transform.rotation = lookRot * Quaternion.inverse(rotationOffset);

或者，由于UpdateRotation调用的频率可能会比调用的频率高得多StoreOffset，因此请在分配之前进行求反：

rotationOffsetInverse = Quaternion.inverse(Quaternion.Inverse(transform.rotation) 
                                           * lookRot);
// ...
transform.rotation = lookRot * rotationOffsetInverse;

因此，总共：

public Vector3 anchorPoint = Vector3.zero;
public Vector3 controlPoint = Vector3.left;

Quaternion rotationOffsetInverse = Quaternion.identity;

Quaternion GetControlLookRot()
{
    // The unit vector pointing from the controlPoint to it's anchorPoint
    Vector3 controlFwd = (anchorPoint - controlPoint).normalized;

    // Generate a rotation using the direction vector while respecting the 
    // objects local up.
    return Quaternion.LookRotation(controlFwd, transform.up);
}

// Called when the object is "attached" to the anchor to store the difference between 
// its rotation and the directional vector from the control to the anchor
public void StoreOffset()
{
    rotationOffsetInverse = Quaternion.inverse(Quaternion.Inverse(transform.rotation) 
                                        * GetControlLookRot());
}

// Called any time the control point is moved to update the objects rotation
public void UpdateRotation() 
{
    // Assign the new look rotation to the object then apply the offset rotation.
    transform.rotation = GetControlLookRot() * rotationOffsetInverse;
}