UrhoSharpで作るHoloLens用の積木アプリ - SpatialMappingと簡単なイベント ref: http://qiita.com/miyaura/items/00447014492ea3562f65

BlockStackingSamples.cs

// Copyright(c) 2017 Takahiro Miyaura
// Released under the MIT license
// http://opensource.org/licenses/mit-license.php
public override void OnSurfaceAddedOrUpdated(SpatialMeshInfo surface, Model generatedModel)
{
    var isNew = false;
    StaticModel staticModel = null;

    //check already created by Id.
    var node = environmentNode.GetChild(surface.SurfaceId, false);
    if (node != null)
    {
        //get StaticModel.
        staticModel = node.GetComponent<StaticModel>();
    }
    else
    {
        //if it is new,create node.
        isNew = true;
        node = environmentNode.CreateChild(surface.SurfaceId);
        staticModel = node.CreateComponent<StaticModel>();
    }
    node.Position = surface.BoundsCenter;
    node.Rotation = surface.BoundsRotation;
    staticModel.Model = generatedModel;

    if (isNew)
    {
        //set collisionShape.
        staticModel.SetMaterial(spatialMaterial);
        var rigidBody = node.CreateComponent<RigidBody>();
        rigidBody.RollingFriction = 0.5f;
        rigidBody.Friction = 0.5f;
        var collisionShape = node.CreateComponent<CollisionShape>();
        collisionShape.SetTriangleMesh(generatedModel, 0, Vector3.One, Vector3.Zero, Quaternion.Identity);
    }
}

Programs.cs

// Copyright(c) 2017 Takahiro Miyaura
// Released under the MIT license
// http://opensource.org/licenses/mit-license.php
using System;
using Windows.ApplicationModel.Core;
using Urho;

namespace UrhnoBlockStackingSamples
{
    internal class Program
    {
        [MTAThread]
        private static void Main()
        {
            var appViewSource = new UrhoAppViewSource<BlockStackingSamples>();
            CoreApplication.Run(appViewSource);
        }
    }
}