Destroy Anchors in Unity ARCore - unity3d

I have a project that places a game object on the position a user touches the screen. An anchor is made as such:
private Anchor anchor;
anchor = detectedPlane.CreateAnchor (new Pose (anchorPosition, Quaternion.identity));
transform.position = anchorPosition;
transform.SetParent (anchor.transform);
Right before creating an anchor when a user touches the screen the second time or any number of times after that, I make sure to destroy the anchor with the following code.
if (anchor != null) {
Destroy(anchor);
}
However, when I test my code on Instant Preview, all of the anchors remain after I touch the screen multiple times. Is this the right way of destroying anchors?

Android
If you want to remove an AnchorNode from a scene then parent.removeChild(child) or node.setParent(null) is the recommended wayin Android ARCore.
To get ARCore to stop tracking an Anchor, you can use yourAnchor.detach().
More details here - Android ARCore
https://developers.google.com/ar/reference/java/com/google/ar/core/Anchor.html#detach()
Unity
The Trackable class in unity has a method to create Anchors but not to destroy them. However, the approach that seems to be used is to destroy the Unity GameObject that represent the Anchor.
See an example from the Unity ARCore SDK here: https://github.com/google-ar/arcore-unity-sdk/blob/9448df3e371e7e04a3e99ed6745890021d8f3e32/Assets/GoogleARCore/Examples/ObjectManipulation/Scripts/Manipulators/TranslationManipulator.cs
An extract of the relevant code:
GameObject oldAnchor = transform.parent.gameObject;
Pose desiredPose = m_LastHit.Pose;
Vector3 desiredLocalPosition = transform.parent.InverseTransformPoint(desiredPose.position);
if (desiredLocalPosition.magnitude > MaxTranslationDistance)
{
desiredLocalPosition = desiredLocalPosition.normalized * MaxTranslationDistance;
}
desiredPose.position = transform.parent.TransformPoint(desiredLocalPosition);
Anchor newAnchor = m_LastHit.Trackable.CreateAnchor(desiredPose);
transform.parent = newAnchor.transform;
Destroy(oldAnchor);

Related

Unity / Mirror - Is there a way to keep my camera independent from the player object's prefab after start?

I'm currently trying to create a multiplayer game using mirror!
So far I've been successful in creating a lobby and set up a simple character model with a player locomotion script I've taken and learnt inside out from Sebastian Graves on YouTube (you may know him as the dark souls III tutorial guy)
This player locomotion script uses unity's package 'Input System' and is also dependent on using the camera's .forward and .right directions to determine where the player moves and rotates instead of using forces on the rigidbody. This means you actually need the camera free in the scene and unparented from the player.
Here is my HandleRotation() function for rotating my character (not the camera's rotation function):
private void HandleRotation()
{
// target direction is the way we want our player to rotate and move // setting it to 0
Vector3 targetDirection = Vector3.zero;
targetDirection = cameraManager.cameraTransform.forward * inputHandler.verticalInput;
targetDirection += cameraManager.cameraTransform.right * inputHandler.horizontalInput;
targetDirection.Normalize();
targetDirection.y = 0;
if (targetDirection == Vector3.zero)
{
// keep our rotation facing the way we stopped
targetDirection = transform.forward;
}
// Quaternion's are used to calculate rotations
// Look towards our target direction
Quaternion targetRotation = Quaternion.LookRotation(targetDirection);
// Slerp = rotation between current rotation and target rotation by the speed you want to rotate * constant time regardless of framerates
Quaternion playerRotation = Quaternion.Slerp(transform.rotation, targetRotation, rotationSpeed * Time.deltaTime);
transform.rotation = playerRotation;
}
It's also worth mentioning I'm not using cinemachine however I'm open to learning cinemachine as it may be beneficial in the future.
However, from what I've learnt and managed to find about mirror is that you have to parent the Main Camera under your player object's prefab so that when multiple people load in, multiple camera's are created. This has to happen on a Start() function or similar like OnStartLocalPlayer().
public override void OnStartLocalPlayer()
{
if (mainCam != null)
{
// configure and make camera a child of player
mainCam.orthographic = false;
mainCam.transform.SetParent(cameraPivotTransform);
mainCam.transform.localPosition = new Vector3(0f, 0f, -3f);
mainCam.transform.localEulerAngles = new Vector3(0f, 0f, 0f);
cameraTransform = GetComponentInChildren<Camera>().transform;
defaultPosition = cameraTransform.localPosition.z;
}
}
But of course, that means that the camera is no longer independent to the player and so what ends up happening is the camera rotates when the player rotates.
E.g. if I'm in game and looking to the right of my player model and then press 'w' to walk in the direction the camera is facing, my camera will spin with the player keeping the same rotation while my player spins in order to try and walk in the direction the camera is facing.
What my question here would be: Is there a way to create a system using mirror that doesn't require the camera to be parented to the player object prefab on start, and INSTEAD works by keeping it independent in the scene?
(I understand that using forces on a rigidbody is another method of creating a player locomotion script however I would like to avoid that if possible)
If anybody can help that would be greatly appreciated, Thank You! =]
With the constraint of your camera being attached to the player you will have to adapt the camera logic. What you can do is instantiate a proxy transform for the camera and copy that transforms properties to your camera, globally, every frame. The parent constraint component might do this for you. Then do all your transformations on that proxy.
Camera script with instantiation:
Transform proxy;
void Start(){
proxy = (new GameObject()).transform;
}
void Update(){
//transformations on proxy
transform.position = proxy.position;
transform.rotation = proxy.rotation;
}

Teleporting in Unity3d

enter image description here I am instantiating prefabs and listing them on a scroll list. I am trying to teleport the player to instantiated prefab position when I click its reference on scroll list listing?
All suggestions are welcome.
From what I understand about your problem (explained in the comments rather than the question), you should be able to do this:
You can instantaneously move an object camera by setting its transform's position to the instantiated prefab's position when the click has occurred. For a camera, you probably have the camera view in X and Y dimension, so you want to move it to the new X and Y position but leave the Z-position as it is.
One potential solution: Add the following script to the GameObject with your Button component. Then add an event-listener on the Button component that points to the newly added script component and choose the MyTeleportingButton.OnClick as the target method. You also need to drag in the camera as a reference in the new script component.
public class MyTeleportingButton : MonoBehaviour
{
public GameObject camera;
public void OnClick()
{
// casting to Vector2 in order to move in 2D only
var currentPosition = camera.transform.position;
var newPosition = transform.position;
// set same depth as camera
newPosition.z = currentPosition.z;
camera.transform.position = newPosition;
}
}

How to control oculus rotation and potition in unity 5.3.x

I want to control the rotation and position of the Oculus DK2 in Unity 5.3 over. It doesn't seems to be trivial, I've already tried all I could find on unity forum, but nothing seems to works. The CameraRig script doesn't look to do anything when i change it. I want to disable all rotation and position because I have a mocap system that more reliable for those things.
Need some help!
To be able to control the pose your camera must be represented by using a OVRCameraRig that is included with the OVRPlugin for Unity 5.
Once you have that you can use the UpdatedAnchors event from the camera to transform the mocap data on to the camera position, just overwrite the value of OVRCameraRig.trackerAnchor for the head and OVRCameraRig.leftHandAnchor and OVRCameraRig.rightEyeAnchorfor hand positions if your suit supports those.
public class MocapController : MonoBehavior
{
public OVRCameraRig camera; //Drag camera rig object on to the script in the editor.
void Awake()
{
camera.UpdatedAnchors += UpdateAnchors
}
void UpdatedAnchors(OVRCameraRig rigToUpdate)
{
Transform headTransform = GetHeadTransform(); //Write yourself
Transform lHandTransform = GetLHandTransform(); //Write yourself
Transform rHandTransform = GetRHandTransform(); //Write yourself
rigToUpdate.trackerAnchor = headTransform;
rigToUpdate.leftHandAnchor= lHandTransform;
rigToUpdate.rightHandAnchor= rHandTransform;
}
}

Unity3D Raycasting with Oculus Rift Integration / Measuring the distance

I want to measure the distance between two points in Unity3D Game Engine using the Oculus Rift. The points are targeted by the user by looking at point A, pressing alpha1 on the keyboard and B, pressing alpha2 on the keyboard. I got this far:
#pragma strict
private var measuring = false;
private var startPoint : Vector3;
private var dist;
function Update() {
var hit : RaycastHit;
if (Input.GetKeyDown(KeyCode.Alpha1)) {
dist = 0.0f;
if (Physics.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition), hit)) {
// if (Physics.Raycast(transform.position, transform.forward, hit, 10)) {
measuring = true;
startPoint = hit.point;
}
}
if (measuring && Input.GetKeyDown(KeyCode.Alpha2)) {
if (Physics.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition), hit)) {
// if (Physics.Raycast(transform.position, transform.forward, hit, 10)) {
dist = Vector3.Distance(startPoint, hit.point);
}
}
}
function OnGUI() {
if (measuring) {
GUI.Label(Rect(50,50,180,50), "Distance: " + dist.ToString());
}
}
My problem is, that this code only works with the standard main camera object, but I want to use the Oculus integrated OVRCameraRig. I get the following exception message:
NullReferenceException: Object reference not set to an instance of an object
MeasureInGame.Update () (at Assets/MeasureInGame.js:11)
I found a solution on this site: https://kaharri.com/unity-gaming-shootingaiming-part3-oculus/ I created a ShotSpawner object as a child of OVRCameraRig (this should act like a gun in front of the camera) and changed the Raycast to
Physics.Raycast(transform.position, transform.forward, hit, 10)
to get the users view. But it also doesn't seem to work.
How can I get the aiming done with the Oculus a Main Camera. And is it correct that I strictly need to have a collider on my objects to be measured or is there a solution without collider?
Greetings
First of all - are you really using the mouse with Oculus? Of course you can, but the standard way is to look at the selected object (cursor is in the center of viewport). Cast the ray from the "middle" eye in the oculus integration - it's the object that is the parent to the left and right eyes. Use this ray instead of the one from Camera.main.ScreenPointToRay:
// add a reference to the middleEyeGameobject
// in your class and link it in the inspector
var ray=new Ray(middleEyeGameobject.transform.position, middleEyeGameobject.transform.forward);
Also, you don't have to specify the distance with hit raycast (remove the fourth parameter to Physics.Raycast).
And for the additional question yes, everything has to have a collider with Physics.Raycast. And yes, there are other ways to do this, but the built in ones (2) still require colliders (or similar), although they can be virtual, not attached to objects.
It's best to use colliders, perhaps on their own layer.
The NullReferenceException you are getting is because you are using Camera.main.ScreenPointToRay(Input.mousePosition) , camera.main uses the MainCamera tag which is not set for your OVRCameraRig. You can set tag of this camera as mainCamera if OVRCameraRig is supposed to be your mainCamera or otherwise you can take reference of this camera (OVRCameraRig) and use cameraRef.ScreenPointToRay(Input.mousePosition). :)

Unity3D OffNavMesh jump issue

I have set up Unity navigation meshes (four planes), navigation agent (sphere) and set up automatic and manual off mesh links. It should now jump between meshes. It does jump between meshes, but it does that in straight lines.
In other words, when agent comes to an edge, instead of actually jumping up (like off mesh link is drawn) it just moves straight in line but a bit faster. I tried moving one plane higher than others, but sphere still was jumping in straight line.
Is it supposed to be like this? Is it possible to set up navigation to jump by some curve? Or should I try to implement that myself?
I came by this question, and had to dig through the Unity sample. I just hope to make it easier for people by extracting the important bits.
To apply your own animation/transition across a navmesh link, you need to tell Unity that you will handle all offmesh link traversal, then add code that regularly checks to see if the agent is on an offmesh link. Finally, when the transition is complete, you need to tell Unity you've moved the agent, and resume normal navmesh behaviour.
The way you handle link logic is up to you. You can just go in a straight line, have a spinning wormhole, whatever. For jump, unity traverses the link using animation progress as the lerp argument, this works pretty nicely. (if you're doing looping or more complex animations, this doesn't work so well)
The important unity bits are:
_navAgent.autoTraverseOffMeshLink = false; //in Start()
_navAgent.currentOffMeshLinkData; //the link data - this contains start and end points, etc
_navAgent.CompleteOffMeshLink(); //Tell unity we have traversed the link (do this when you've moved the transform to the end point)
_navAgent.Resume(); //Resume normal navmesh behaviour
Now a simple jump sample...
using UnityEngine;
[RequireComponent(typeof(NavMeshAgent))]
public class NavMeshAnimator : MonoBehaviour
{
private NavMeshAgent _navAgent;
private bool _traversingLink;
private OffMeshLinkData _currLink;
void Start()
{
// Cache the nav agent and tell unity we will handle link traversal
_navAgent = GetComponent<NavMeshAgent>();
_navAgent.autoTraverseOffMeshLink = false;
}
void Update()
{
//don't do anything if the navagent is disabled
if (!_navAgent.enabled) return;
if (_navAgent.isOnOffMeshLink)
{
if (!_traversingLink)
{
//This is done only once. The animation's progress will determine link traversal.
animation.CrossFade("Jump", 0.1f, PlayMode.StopAll);
//cache current link
_currLink = _navAgent.currentOffMeshLinkData;
//start traversing
_traversingLink = true;
}
//lerp from link start to link end in time to animation
var tlerp = animation["Jump"].normalizedTime;
//straight line from startlink to endlink
var newPos = Vector3.Lerp(_currLink.startPos, _currLink.endPos, tlerp);
//add the 'hop'
newPos.y += 2f * Mathf.Sin(Mathf.PI * tlerp);
//Update transform position
transform.position = newPos;
// when the animation is stopped, we've reached the other side. Don't use looping animations with this control setup
if (!animation.isPlaying)
{
//make sure the player is right on the end link
transform.position = _currLink.endPos;
//internal logic reset
_traversingLink = false;
//Tell unity we have traversed the link
_navAgent.CompleteOffMeshLink();
//Resume normal navmesh behaviour
_navAgent.Resume();
}
}
else
{
//...update walk/idle animations appropriately ...etc
Its recommended to solve your problems via animation. Just create a Jump animation for your object, and play it at the correct time.
The position is relative, so if you increase the Y-position in your animation it will look like the object is jumping.
This is also how the Unity sample is working, with the soldiers running around.
Not sure what version of unity you are using but you could also try this, I know it works just fine in 4:
string linkType = GetComponent<NavMeshAgent>().currentOffMeshLinkData.linkType.ToString();
if(linkType == "LinkTypeJumpAcross"){
Debug.Log ("Yeah im in the jump already ;)");
}
also just some extra bumf for you, its best to use a proxy and follow the a navAgent game object:
Something like:
AIMan = this.transform.position;
AI_Proxy.transform.position = AIMan;
And also be sure to use:
AI_Proxy.animation["ProxyJump"].blendMode = AnimationBlendMode.Additive;
If you are using the in built unity animation!
K, that's my good deed for this week.
Fix position in update()
if (agent.isOnOffMeshLink)
{
transform.position = new Vector3(transform.position.x, 0f, transform.position.z);
}