Unity AR Foundation TrackedImage Rotation Issue Need Help
I am developing an Android application using AR Foundation in Unity. I am generating objects through TrackedImage, but the rotation of the objects varies depending on the initial position of the device, even if the same rotation values are applied.
For example, if I launch the application while facing north, south, east, or west, and then recognize an image, the object’s rotation appears as intended. However, if I launch the application while facing a diagonal direction, the object’s rotation is slightly off.
The red rectangle represents the desired direction, and when I launch the application facing one of the cardinal directions (north, south, east, or west), it appears like the red rectangle. However, when I launch the application facing any other direction, the issue arises where the object appears like the blue rectangle.
Below is the code I wrote, where objs[0] is the object that is aligned with the +z direction at the initial execution.
currentForward is used to capture the current forward direction.
Objects are generated in the ±x, ±y, and ±z directions, and using a raycast from the camera, I check which direction the user is currently facing.
When I use trackedImage.transform.position for spawnedObject.transform.position, the result is not what I want, and the outcome changes depending on the direction the app is launched. Therefore, I am currently hardcoding by adding specific values to the camera’s position.
Finally, I add snappedAngle + 90 to the rotation because the model, exported from Blender, has a -90 degree rotation, so I add 90 to compensate for that.
Is there a solution to this problem?
if (trackedImage.trackingState == TrackingState.Tracking)
{
Vector3 rotationAngles = Camera.main.transform.rotation.eulerAngles;
trackedPosition = trackedImage.transform.position;
GameObject spawnedObject = Instantiate(arObjectPrefab[0]);
Vector3 directionToB = trackedImage.transform.position - objs[0].transform.position;
directionToB.Normalize();
float angle = Vector3.Angle(forwardA, directionToB);
Vector3 cross = Vector3.Cross(forwardA, directionToB);
if (cross.y < 0)
{
angle = -angle;
}
if (angle < 0)
{
angle += 360;
}
float snappedAngle = Mathf.Round(angle / 90) * 90;
float cameraAngle;
if (rotationAngles.y < 0)
{
cameraAngle = Mathf.Round(rotationAngles.y % -90);
}
else
{
cameraAngle = Mathf.Round(rotationAngles.y % 90);
}
switch (currentForward)
{
case "+x":
spawnedObject.transform.position = Camera.main.transform.position + GlobalVariable.Instance.room_offset_x;
break;
case "-x":
spawnedObject.transform.position = Camera.main.transform.position + GlobalVariable.Instance.room_offset_nx;
break;
case "+z":
spawnedObject.transform.position = Camera.main.transform.position + GlobalVariable.Instance.room_offset_z;
break;
case "-z":
spawnedObject.transform.position = Camera.main.transform.position + GlobalVariable.Instance.room_offset_nz;
break;
}
spawnedObject.transform.rotation = Quaternion.Euler(0f, snappedAngle + 90, 0f);
}
The code related to obj[] is as follows.
private void Start()
{
GameObject obj = GameObject.CreatePrimitive(PrimitiveType.Cube);
obj.transform.localScale = new Vector3(0.1f, 0.5f, 0.5f);
obj.name = "+x";
obj.GetComponent<Renderer>().enabled = false;
objs.Add(obj);
obj = GameObject.CreatePrimitive(PrimitiveType.Cube);
obj.transform.localScale = new Vector3(0.1f, 0.5f, 0.5f);
obj.name = "-x";
obj.GetComponent<Renderer>().enabled = false;
objs.Add(obj);
obj = GameObject.CreatePrimitive(PrimitiveType.Cube);
obj.transform.localScale = new Vector3(0.5f, 0.1f, 0.5f);
obj.name = "+y";
obj.GetComponent<Renderer>().enabled = false;
objs.Add(obj);
obj = GameObject.CreatePrimitive(PrimitiveType.Cube);
obj.transform.localScale = new Vector3(0.5f, 0.1f, 0.5f);
obj.name = "-y";
obj.GetComponent<Renderer>().enabled = false;
objs.Add(obj);
obj = GameObject.CreatePrimitive(PrimitiveType.Cube);
obj.transform.localScale = new Vector3(0.5f, 0.5f, 0.1f);
obj.name = "+z";
obj.GetComponent<Renderer>().enabled = false;
objs.Add(obj);
obj = GameObject.CreatePrimitive(PrimitiveType.Cube);
obj.transform.localScale = new Vector3(0.5f, 0.5f, 0.1f);
obj.name = "-z";
obj.GetComponent<Renderer>().enabled = false;
objs.Add(obj);
}
private void Update()
{
foreach (GameObject i in objs)
{
switch (i.name)
{
case "+x":
i.transform.position = Camera.main.transform.position + new Vector3(0.25f, 0, 0);
break;
case "-x":
i.transform.position = Camera.main.transform.position + new Vector3(-0.25f, 0, 0);
break;
case "+y":
i.transform.position = Camera.main.transform.position + new Vector3(0, 0.25f, 0);
break;
case "-y":
i.transform.position = Camera.main.transform.position + new Vector3(0, -0.25f, 0);
break;
case "+z":
i.transform.position = Camera.main.transform.position + new Vector3(0, 0, 0.25f);
break;
case "-z":
i.transform.position = Camera.main.transform.position + new Vector3(0, 0, -0.25f);
break;
}
}
}