Mixed Reality Utility Kit – Instant placement with Environment Raycasting API

• Understand the concept of Environment Raycasting.
• Learn about the EnvironmentRaycastManager component (raycasts, box placement, overlap checks).
• Implement a script to place an object into your space.

• Platform Support: Meta Quest 3/3S, Unity 2022.3 LTS or later, Oculus XR Plugin OR Unity OpenXR Meta (when using Unity 6)
• Meta XR SDK: Available in MRUK version 71 or later
• Field of View: Only rays within the headset’s depth camera frustum will return hits; outside rays yield HitPointOutsideOfCameraFrustum or NoHit.

• Raycast: Shoots a virtual ray into the live depth buffer and reports the first intersection point. You’ll use this for pinpointing where on a surface to anchor your content.
• PlaceBox: Aligns an axis-aligned box (e.g., the bounds of a UI panel or furniture) with a detected flat surface, then checks whether that box would fit without colliding with real-world geometry.
• CheckBox: Performs an overlap test for a proposed bounding box, letting you quickly reject placements that would intersect walls, tables, or other obstacles.
• IsSupported: Returns true only on devices and runtimes where environment raycasting is available, so you can safely disable or fallback on unsupported platforms.

// Cast a single ray against live depth data
bool Raycast(Ray ray, out EnvironmentRaycastHit hitInfo, float maxDistance = 100f);

// Try to place an axis-aligned box on a flat surface
bool PlaceBox(Ray ray, Vector3 boxSize, Vector3 upwards, out EnvironmentRaycastHit hitInfo);

// Check if an axis-aligned box overlaps the environment
bool CheckBox(Vector3 center, Vector3 halfExtents, Quaternion orientation);

// True if environment raycasts are supported on this device
public static bool IsSupported { get; }

Raycast

A raycast returns an EnvironmentRaycastHit struct containing point, normal and normalConfidence, along with a status enum that conveys errors (NotReady, NotSupported, Occluded, etc.).

PlaceBox

Use PlaceBox to align a box on a flat area: it adjusts orientation based on upwards, then checks for collisions to ensure the box fits. CheckBox returns overlap only.

1. Follow the basic Getting Started guide.
2. Create an empty GameObject and add the EnvironmentRaycastManager components to it.
3. Open the Project Setup Tool (PST) and fix all outstanding warnings.
4. Create a new script called InstantPlacementController and add it to your GameObject.

• rightControllerAnchor: This is the origin of our raycast. In this case we use the transform of the right hand, but you can use any other transform. The right hand anchor can be found in the OVRCameraRig GameObject under TrackingSpace.
• prefabToPlace: This is the prefab that will be instantiated when the raycast hits a surface. In this case we use a simple cube, but you can use any other prefab.
• raycastManager: This is the EnvironmentRaycastManager component that we added to the GameObject in the previous step.

using Meta.XR;
using UnityEngine;

public class InstantPlacementController : MonoBehaviour
{
    public Transform rightControllerAnchor;
    public GameObject prefabToPlace;
    public EnvironmentRaycastManager raycastManager;
}

private void Update()
{
    if (OVRInput.GetDown(OVRInput.RawButton.RIndexTrigger))
    {
        var ray = new Ray(
            rightControllerAnchor.position,
            rightControllerAnchor.forward
        );

        TryPlace(ray);
    }
}

private void TryPlace(Ray ray)
{
    if (raycastManager.Raycast(ray, out var hit))
    {
        var objectToPlace = Instantiate(prefabToPlace);
        objectToPlace.transform.SetPositionAndRotation(
            hit.point,
            Quaternion.LookRotation(hit.normal, Vector3.up)
        );

        // If no MRUK component is present in the scene, we add an OVRSpatialAnchor component
        // to the instantiated prefab to anchor it in the physical space and prevent drift.
        if (MRUK.Instance?.IsWorldLockActive != true)
         {
                 objectToPlace.AddComponent<OVRSpatialAnchor>();
         }
    }
}

using Meta.XR.MRUtilityKit;
using UnityEngine;

public class InstantPlacementController : MonoBehaviour
{
    public Transform rightControllerAnchor;
    public GameObject prefabToPlace;
    public EnvironmentRaycastManager raycastManager;

    private void Update()
    {
        if (OVRInput.GetDown(OVRInput.RawButton.RIndexTrigger))
        {
            var ray = new Ray(
                rightControllerAnchor.position,
                rightControllerAnchor.forward
            );

            TryPlace(ray);
        }
    }

    private void TryPlace(Ray ray)
    {
        if (raycastManager.Raycast(ray, out var hit))
        {
            var objectToPlace = Instantiate(prefabToPlace);
            objectToPlace.transform.SetPositionAndRotation(
                hit.point,
                Quaternion.LookRotation(hit.normal, Vector3.up)
            );

            if (MRUK.Instance?.IsWorldLockActive != true)
            {
                objectToPlace.AddComponent<OVRSpatialAnchor>();
            }
        }
    }
}

Content Placement MR Motif

The Instant Content Placement scene shows Depth Raycasting to detect surfaces and a custom shader that renders a shadow below the object, cutting off at real geometry edges for realistic immersion without manual scanning.

View sample

Environment Panel Placement

This sample demonstrates Environment Raycasting (Beta) to place UI panels in your environment. It casts a ray from the controller and, on a vertical-hit normal, uses PlaceBox to stick the panel. If no vertical surface is hit, CheckBox ensures the panel won’t intersect real-world geometry.

View sample

// Cast a ray from your controller
var ray = new Ray(controller.position, controller.forward);

// Define the panel’s local size (width, height, depth)
Vector3 panelSize = new Vector3(0.5f, 0.1f, 0.3f);

// 'up' keeps the panel upright after placement
Vector3 up = Vector3.up;

if (_raycastManager.PlaceBox(ray, panelSize, up, out var hitInfo))
{
    // Instantiate and orient the panel at the hit point
    var panel = Instantiate(panelPrefab);
    panel.transform.SetPositionAndRotation(
        hitInfo.point,
        Quaternion.LookRotation(hitInfo.normal, up)
    );
}
else
{
    Debug.Log("No suitable flat area found for panel.");
}

// Desired spawn position and cube half‑extents
Vector3 spawnPos = hitInfo.point;
Vector3 halfExtents = Vector3.one * 0.5f;

// Keep cube axis‑aligned
Quaternion orientation = Quaternion.identity;

if (_raycastManager.CheckBox(spawnPos, halfExtents, orientation))
{
    Debug.Log("Cube overlaps environment—choose a different spot.");
}
else
{
    Instantiate(cubePrefab, spawnPos, orientation);
}

• Overview Get an overview of MRUK’s key areas and features.
• Getting Started Set up your project, install MRUK, and understand space setup with available Building Blocks.
• Manage Scene Data Work with MRUKRoom, EffectMesh, anchors, and semantic labels to reflect room structure.

• Place Content with Scene Combine spatial data with placement logic to add interactive content in the right places.
• Manipulate Scene Visuals Replace or remove geometry, apply effects, and adapt scenes using semantics and EffectMesh.
• Track Objects in MRUK Track keyboards using MRUK-trackables.

• Share Your Space with Others Use MRUK’s Space Sharing API to sync scene geometry across multiple users.
• Debug Your MRUK App Use tools like the Scene Debugger and EffectMesh to validate anchor data and scene structure.

• MRUK Samples Explore sample scenes like NavMesh, Virtual Home, Scene Decorator, and more.
• Mixed Reality Motifs Instant Content Placement.

• Mixed Reality Best Practices Design MR apps that are comfortable, intuitive, and immersive.