Custom scene navigation commands
SetObserver.vb
' Copyright 2010 ESRI
' 
' All rights reserved under the copyright laws of the United States
' and applicable international laws, treaties, and conventions.
' 
' You may freely redistribute and use this sample code, with or
' without modification, provided you include the original copyright
' notice and use restrictions.
' 
' See the use restrictions.
' 

Imports ESRI.ArcGIS.Analyst3D
Imports ESRI.ArcGIS.GeomeTry
Imports ESRI.ArcGIS.Controls
Imports ESRI.ArcGIS.ADF.BaseClasses
Imports ESRI.ArcGIS.ADF.CATIDs
Imports System.Runtime.InteropServices

<ComClass(SetObserver.ClassId, SetObserver.InterfaceId, SetObserver.EventsId)> _
Public NotInheritable Class SetObserver
    Inherits BaseTool

#Region "COM GUIDs"
    ' These  GUIDs provide the COM identity for this class 
    ' and its COM interfaces. If you change them, existing 
    ' clients will no longer be able to access the class.
    Public Const ClassId As String = "0120A73E-6E11-4B2A-9F57-B095EAAA4180"
    Public Const InterfaceId As String = "CFCD3896-B61A-4B8F-8B64-95D1229AB082"
    Public Const EventsId As String = "162DEDA7-F4C0-4B51-8F1B-05151A10D704"
#End Region
#Region "COM Registration Function(s)"
    <ComRegisterFunction(), ComVisibleAttribute(False)> _
    Public Shared Sub RegisterFunction(ByVal registerType As Type)
        ' Required for ArcGIS Component Category Registrar support
        ArcGISCategoryRegistration(registerType)

        'Add any COM registration code after the ArcGISCategoryRegistration() call

    End Sub

    <ComUnregisterFunction(), ComVisibleAttribute(False)> _
    Public Shared Sub UnregisterFunction(ByVal registerType As Type)
        ' Required for ArcGIS Component Category Registrar support
        ArcGISCategoryUnregistration(registerType)

        'Add any COM unregistration code after the ArcGISCategoryUnregistration() call

    End Sub

#Region "ArcGIS Component Category Registrar generated code"
    ''' <summary>
    ''' Required method for ArcGIS Component Category registration -
    ''' Do not modify the contents of this method with the code editor.
    ''' </summary>
    Private Shared Sub ArcGISCategoryRegistration(ByVal registerType As Type)
        Dim regKey As String = String.Format("HKEY_CLASSES_ROOT\CLSID\{{{0}}}", registerType.GUID)
        ControlsCommands.Register(regKey)

    End Sub
    ''' <summary>
    ''' Required method for ArcGIS Component Category unregistration -
    ''' Do not modify the contents of this method with the code editor.
    ''' </summary>
    Private Shared Sub ArcGISCategoryUnregistration(ByVal registerType As Type)
        Dim regKey As String = String.Format("HKEY_CLASSES_ROOT\CLSID\{{{0}}}", registerType.GUID)
        ControlsCommands.Unregister(regKey)

    End Sub

#End Region
#End Region

    Private m_pCursor As System.Windows.Forms.Cursor
    Private m_pSceneHookHelper As ISceneHookHelper

  ' A creatable COM class must have a Public Sub New() 
  ' with no parameters, otherwise, the class will not be 
  ' registered in the COM registry and cannot be created 
  ' via CreateObject.
    Public Sub New()
        MyBase.New()

        MyBase.m_category = "Sample_SceneControl(VB.NET)"
        MyBase.m_caption = "Set Observer"
        MyBase.m_toolTip = "Set Observer"
        MyBase.m_name = "Sample_SceneControl(VB.NET)/SetObserver"
        MyBase.m_message = "Set observer position to selected point"

        'Load resources
        Dim res() As String = GetType(SetObserver).Assembly.GetManifestResourceNames()
        If res.GetLength(0) > 0 Then
            MyBase.m_bitmap = New System.Drawing.Bitmap(GetType(SetObserver).Assembly.GetManifestResourceStream("SceneToolsVB.observer.bmp"))
        End If
        m_pCursor = New System.Windows.Forms.Cursor(GetType(SetObserver).Assembly.GetManifestResourceStream("SceneToolsVB.observer.cur"))

        m_pSceneHookHelper = New SceneHookHelperClass

    End Sub

    Public Overrides Sub OnCreate(ByVal hook As Object)
        m_pSceneHookHelper.Hook = hook
    End Sub

    Public Overrides ReadOnly Property Enabled() As Boolean
        Get
            If (m_pSceneHookHelper.Hook Is Nothing Or m_pSceneHookHelper.Scene Is Nothing) Then
                Return False
            Else
                Dim pCamera As ICamera = CType(m_pSceneHookHelper.Camera, ICamera)

                'Disable if orthographic (2D) view
                If (pCamera.ProjectionType = esri3DProjectionType.esriOrthoProjection) Then
                    Return False
                Else
                    Return True
                End If
            End If

        End Get
    End Property

    Public Overrides ReadOnly Property Cursor() As Integer
        Get
            Return m_pCursor.Handle.ToInt32()
        End Get
    End Property

    Public Overrides Function Deactivate() As Boolean
        Return True
    End Function

    Public Overrides Sub OnMouseUp(ByVal Button As Integer, ByVal Shift As Integer, ByVal X As Integer, ByVal Y As Integer)
        'Get the scene graph
        Dim pSceneGraph As ISceneGraph = CType(m_pSceneHookHelper.SceneGraph, ISceneGraph)

        Dim pNewObs As IPoint = Nothing
        Dim pOwner As Object = Nothing, pObject As Object = Nothing

        'Translate screen coordinates into a 3D point
        pSceneGraph.Locate(pSceneGraph.ActiveViewer, X, Y, esriScenePickMode.esriScenePickAll, True, pNewObs, pOwner, pObject)

        If (pNewObs Is Nothing) Then
            Return
        End If

        'Get the scene viewer's camera
        Dim pCamera As ICamera = CType(m_pSceneHookHelper.Camera, ICamera)

        'Get the camera's old observer
        Dim pOldObs As IPoint = CType(pCamera.Observer, IPoint)

        'Get the duration in seconds of last redraw
        'and the average number of frames per second
        Dim dlastFrameDuration, dMeanFrameRate As Double
        pSceneGraph.GetDrawingTimeInfo(dlastFrameDuration, dMeanFrameRate)

        If (dlastFrameDuration < 0.01) Then
            dlastFrameDuration = 0.01
        End If

        Dim iSteps As Integer
        iSteps = 2 / dlastFrameDuration

        If (iSteps < 1) Then
            iSteps = 1
        End If

        If (iSteps > 60) Then
            iSteps = 60
        End If

        Dim dxObs, dyObs, dzObs As Double
        dxObs = (pNewObs.X - pOldObs.X) / iSteps
        dyObs = (pNewObs.Y - pOldObs.Y) / iSteps
        dzObs = (pNewObs.Z - pOldObs.Z) / iSteps

        'Loop through each step moving the camera's observer from the old
        'position to the new position, refreshing the scene viewer each time

        Dim i As Integer
        For i = 0 To iSteps
            pNewObs.X = pOldObs.X + (i * dxObs)
            pNewObs.Y = pOldObs.Y + (i * dyObs)
            pNewObs.Z = pOldObs.Z + (i * dzObs)
            pCamera.Observer = pNewObs
            pSceneGraph.ActiveViewer.Redraw(True)
        Next i
    End Sub
End Class