Camera Class

public class Camera

// Copyright 2017 Esri.
// 
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
// You may obtain a copy of the License at: http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific
// language governing permissions and limitations under the License.

using Android.App;
using Android.OS;
using Android.Widget;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.UI.Controls;
using System;
using Esri.ArcGISRuntime.Geometry;

namespace ArcGISRuntime.Samples.SceneLayerUrl
{
    [Activity (ConfigurationChanges=Android.Content.PM.ConfigChanges.Orientation | Android.Content.PM.ConfigChanges.ScreenSize)]
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        "ArcGIS scene layer (URL)",
        "Layers",
        "Display an ArcGIS Scene layer from a service.",
        "")]
    public class SceneLayerUrl : Activity
    {
        // Hold a reference to the scene view.
        private SceneView _mySceneView;

        // URL for a service to use as an elevation source.
        private readonly Uri _elevationSourceUrl = new Uri(
            "https://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer");

        // URL for the scene layer.
        private readonly Uri _serviceUri = new Uri(
            "https://tiles.arcgis.com/tiles/P3ePLMYs2RVChkJx/arcgis/rest/services/Buildings_Portland/SceneServer");

        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            Title = "ArcGIS scene layer (URL)";

            CreateLayout();
            Initialize();
        }

        private async void Initialize()
        {
            // Create new Scene.
            Scene myScene = new Scene {Basemap = Basemap.CreateImagery()};

            // Create and add an elevation source for the Scene.
            ArcGISTiledElevationSource elevationSrc = new ArcGISTiledElevationSource(_elevationSourceUrl);
            myScene.BaseSurface.ElevationSources.Add(elevationSrc);

            // Create new scene layer from the URL.
            ArcGISSceneLayer sceneLayer = new ArcGISSceneLayer(_serviceUri);

            // Add created layer to the operational layers collection.
            myScene.OperationalLayers.Add(sceneLayer);

            try
            {
                // Load the layer.
                await sceneLayer.LoadAsync();

                // Get the center of the scene layer.
                MapPoint center = (MapPoint)GeometryEngine.Project(sceneLayer.FullExtent.GetCenter(), SpatialReferences.Wgs84);

                // Create a camera with coordinates showing layer data.
                Camera camera = new Camera(center.Y, center.X, 225, 220, 80, 0);

                // Assign the Scene to the SceneView.
                _mySceneView.Scene = myScene;

                // Set view point of scene view using camera.
                await _mySceneView.SetViewpointCameraAsync(camera);
            }
            catch (Exception e)
            {
                new AlertDialog.Builder(this).SetMessage(e.ToString()).SetTitle("Error").Show();
            }
        }

        private void CreateLayout()
        {
            // Create a new vertical layout for the app.
            LinearLayout layout = new LinearLayout(this) { Orientation = Orientation.Vertical };

            // Add the scene view to the layout.
            _mySceneView = new SceneView(this);
            layout.AddView(_mySceneView);

            // Show the layout in the app.
            SetContentView(layout);
        }
    }
}

// Copyright 2019 Esri.
// 
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
// You may obtain a copy of the License at: http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an 
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific 
// language governing permissions and limitations under the License.

using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Symbology;
using Esri.ArcGISRuntime.UI;
using Xamarin.Forms;

namespace ArcGISRuntimeXamarin.Samples.ScenePropertiesExpressions
{
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        "Scene properties expressions",
        "GraphicsOverlay",
        "Update the orientation of a graphic using scene property rotation expressions.",
        "",
        "rotation", "expression", "heading", "pitch", "scene", "3D", "symbology")]
    public partial class ScenePropertiesExpressions : ContentPage
    {
        public ScenePropertiesExpressions()
        {
            InitializeComponent();
            Initialize();
        }

        private void Initialize()
        {
            // Set up the scene with an imagery basemap.
            MySceneView.Scene = new Scene(Basemap.CreateImagery());

            // Set the initial viewpoint for the scene.
            MapPoint point = new MapPoint(83.9, 28.4, 1000, SpatialReferences.Wgs84);
            Camera initialCamera = new Camera(point, 1000, 0, 50, 0);
            MySceneView.SetViewpointCamera(initialCamera);

            // Create a graphics overlay.
            GraphicsOverlay overlay = new GraphicsOverlay();
            overlay.SceneProperties.SurfacePlacement = SurfacePlacement.Relative;
            MySceneView.GraphicsOverlays.Add(overlay);

            // Add a renderer using rotation expressions.
            SimpleRenderer renderer = new SimpleRenderer();
            renderer.SceneProperties.HeadingExpression = "[HEADING]";
            renderer.SceneProperties.PitchExpression = "[PITCH]";

            // Apply the renderer to the graphics overlay.
            overlay.Renderer = renderer;

            // Create a red cone graphic.
            SimpleMarkerSceneSymbol coneSymbol = SimpleMarkerSceneSymbol.CreateCone(Color.Red, 100, 100);
            coneSymbol.Pitch = -90;
            MapPoint conePoint = new MapPoint(83.9, 28.41, 200, SpatialReferences.Wgs84);
            Graphic cone = new Graphic(conePoint, coneSymbol);

            // Add the cone graphic to the overlay.
            overlay.Graphics.Add(cone);

            // Listen for changes in slider values and update graphic properties.
            HeadingSlider.ValueChanged += (sender, e) => { cone.Attributes["HEADING"] = HeadingSlider.Value; };
            PitchSlider.ValueChanged += (sender, e) => { cone.Attributes["PITCH"] = PitchSlider.Value; };
        }
    }
}

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage
    x:Class="ArcGISRuntimeXamarin.Samples.ScenePropertiesExpressions.ScenePropertiesExpressions"
    xmlns="http://xamarin.com/schemas/2014/forms"
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
    xmlns:esriUI="clr-namespace:Esri.ArcGISRuntime.Xamarin.Forms;assembly=Esri.ArcGISRuntime.Xamarin.Forms"
    xmlns:resources="clr-namespace:Forms.Resources;assembly=ArcGISRuntime">
    <RelativeLayout>
        <esriUI:SceneView
            x:Name="MySceneView"
            Style="{StaticResource MapWithFormStyle}"
            ViewInsets="0" />
        <resources:ResponsiveFormContainer x:Name="FormContainer">
            <StackLayout>
                <Grid>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="*" />
                        <ColumnDefinition Width="200" />
                    </Grid.ColumnDefinitions>
                    <Label
                        Grid.Column="0"
                        Style="{StaticResource LabelStyle}"
                        Text="Heading:" />
                    <Slider
                        x:Name="HeadingSlider"
                        Grid.Column="1"
                        Maximum="360"
                        MaximumTrackColor="Black"
                        Minimum="0"
                        MinimumTrackColor="Black" />
                </Grid>
                <Grid>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="*" />
                        <ColumnDefinition Width="200" />
                    </Grid.ColumnDefinitions>
                    <Label
                        Grid.Column="0"
                        Style="{StaticResource LabelStyle}"
                        Text="Pitch:" />
                    <Slider
                        x:Name="PitchSlider"
                        Grid.Column="1"
                        Maximum="90"
                        MaximumTrackColor="Black"
                        Minimum="-90"
                        MinimumTrackColor="Black" />
                </Grid>
            </StackLayout>
        </resources:ResponsiveFormContainer>
    </RelativeLayout>
</ContentPage>