MagicLeapで床にオブジェクトを配置する方法 #C#

開発環境

Unity : 2019.3.7f1
LuminOS : 0.98.11, APILevel 8
MagicLeap : UnitySDK 0.24.1
MagicLeap : ToolKit 特にバージョン表記等はないので現時点(2020/09/22)での最新

MagicLeapToolKitのDLはこちらから

今回開発したアプリのリポジトリはこちらになります

完成するもの

床を判定するやつ pic.twitter.com/zzhb4lk5g2
— 松本隆介 (@matsumotokaka11) September 21, 2020

下準備

ProjectSettings > MagicLeap > ManifestSettingsにて以下の項目にチェックを入れました

ControllerPose
LowLatencyLightwear
WorldReconstruction

スクリプト等

今回のスクリプトはMagicLeap ToolKitのPlaceOnFloorを改造したものです

素のPlaceOnFloorのままだと初回の床判定以降は床判定を行わないので何度でも床判定を行えるようにしました。

改造したFloorChecker.cs


using System.Collections;
using System.Collections.Generic;
using UnityEngine;

#if PLATFORM_LUMIN
using UnityEngine.XR.MagicLeap;
#endif


namespace FloorCheck
{
    /// <summary>
    /// MagicLeapToolsのFloorOnPlaceを改造したクラス.
    /// 床検知を何度もにできるようにする.
    /// </summary>
    public class FloorChecker : MonoBehaviour
    {
        readonly float HeadLocationIdleThreshold = 0.003f;
        readonly float HeadRotationIdleThreshold = .3f;
        readonly int HistoryCount = 5;
        readonly float HeadIdleRequiredDuration = .2f;

        // Public Properties:
        public Vector3 Location
        {
            get;
            private set;
        }


        [Tooltip("Does content's content match it's transform forward?")]
        [SerializeField] bool flippedForward;


        List<Vector3> headLocationHistory;
        List<Quaternion> headRotationHistory;
        float headLocationVelocity;
        float headRotationVelocity;
        Transform mainCamera;
        bool headLocationIdle;
        bool headRotationIdle;
        bool headTemporarilyIdle;
        bool headIdle;
        bool placementValid;


        //Init:
        void Awake()
        {
            //refs:
            mainCamera = Camera.main.transform;

            //requirements:
            if (FindObjectOfType<MLSpatialMapper>() == null)
            {
                Debug.LogError("PlaceOnFloor requires and instance of the MLSpatialMapper in your scene.");
            }
        }


        //Flow:
        void OnEnable()
        {
            //sets:
            headLocationHistory = new List<Vector3>();
            headRotationHistory = new List<Quaternion>();
        }


        //Loops:
        void Update()
        {
            //let headpose warmup a little:
            if (Time.frameCount < 3)
            {
                return;
            }

            HeadActivityDetermination(); 
        }


        //Coroutines:
        IEnumerator HeadIdleTimeout()
        {
            yield return new WaitForSeconds(HeadIdleRequiredDuration);
            headIdle = true;
        }


        void HeadActivityDetermination()
        {
            //history:
            headLocationHistory.Add(mainCamera.position);
            if (HistoryCount < headLocationHistory.Count)
                headLocationHistory.RemoveAt(0);

            headRotationHistory.Add(mainCamera.rotation);
            if (HistoryCount < headRotationHistory.Count)
                headRotationHistory.RemoveAt(0);

            //location velocity:
            if (headLocationHistory.Count == HistoryCount)
            {
                headLocationVelocity = 0;
                for (int i = 1; i < headLocationHistory.Count; i++)
                {
                    headLocationVelocity += Vector3.Distance(headLocationHistory[i], headLocationHistory[i - 1]);
                }
                headLocationVelocity /= headLocationHistory.Count;

                //idle detection:
                if (headLocationVelocity <= HeadLocationIdleThreshold)
                {
                    if (!headLocationIdle)
                    {
                        headLocationIdle = true;
                    }
                }
                else
                {
                    if (headLocationIdle)
                    {
                        headLocationIdle = false;
                    }
                }
            }

            //rotation velocity:
            if (headRotationHistory.Count == HistoryCount)
            {
                headRotationVelocity = 0;
                for (int i = 1; i < headRotationHistory.Count; i++)
                {
                    headRotationVelocity += Quaternion.Angle(headRotationHistory[i], headRotationHistory[i - 1]);
                }
                headRotationVelocity /= headRotationHistory.Count;

                //idle detection:
                if (headRotationVelocity <= HeadRotationIdleThreshold)
                {
                    if (!headRotationIdle)
                    {
                        headRotationIdle = true;
                    }
                }
                else
                {
                    if (headRotationIdle)
                    {
                        headRotationIdle = false;
                    }
                }
            }

            //absolute idle head determination:
            if (headLocationIdle && headRotationIdle)
            {
                if (!headTemporarilyIdle)
                {
                    headTemporarilyIdle = true;
                    StartCoroutine(HeadIdleTimeout());
                }
            }
            else
            {
                if (headTemporarilyIdle)
                {
                    headIdle = false;
                    headTemporarilyIdle = false;
                    StopCoroutine(HeadIdleTimeout());
                }
            }
        }


        /// <summary>
        /// 指定したRayの位置に床があるか否か、ある場合はその座標も返す.
        /// </summary>
        /// <param name="ray"></param>
        /// <returns></returns>
        public (bool, Vector3) LookingAtFloorDetermination(
            Ray ray)
        {
            //cast to see if we are looking at the floor:
            RaycastHit hit;
            if (Physics.Raycast(ray, out hit))
            {
                MagicLeapTools.SurfaceType surface = MagicLeapTools.SurfaceDetails.Analyze(hit);

                if (surface == MagicLeapTools.SurfaceType.Floor)
                {
                    Location = hit.point;
                    placementValid = true;
                    return (true, Location);
                }
                else
                {
                    placementValid = false;
                    return (false, Vector3.zero);
                }
            }
            else
            {
                placementValid = false;
                return (false, Vector3.zero);
            }
        }


    }
}

FloorCheckerを利用するFloorCheckOnPlaceContent.cs

using System;
using MagicLeapTools;
using UnityEngine;

namespace FloorCheck
{

    /// <summary>
    /// トリガを入力したときに床を判定し、床の場合はオブジェクトを配置するサンプル.
    /// </summary>
    [RequireComponent(typeof(FloorChecker),typeof(AudioSource))]
    public class FloorCheckOnPlaceContent : MonoBehaviour
    {

        [SerializeField] AudioClip pressClip;
        [SerializeField] AudioClip successClip;
        [SerializeField] AudioClip failedClip;
        [SerializeField] GameObject content;
        [SerializeField] Pointer pointer;
        FloorChecker floorChecker;
        AudioSource audio;


        void Start()
        {
            floorChecker = GetComponent<FloorChecker>();
            audio = GetComponent<AudioSource>();
        }


        public void OnTriggerDown()
        {
            audio.PlayOneShot(pressClip);
            (bool onFloor, Vector3 pos ) result = floorChecker.LookingAtFloorDetermination(new Ray(pointer.Origin, pointer.Direction));
            if (result.onFloor)
            {
                audio.PlayOneShot(successClip);
                content.transform.position = result.pos;
            }
            else
            {
                audio.PlayOneShot(failedClip);
            }
        }



    }
}