Custom scene navigation commands
TargetCenter.cs
// 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.
// 

using System;
using ESRI.ArcGIS.Analyst3D;
using ESRI.ArcGIS.Geometry;
using ESRI.ArcGIS.Controls;
using ESRI.ArcGIS.ADF.BaseClasses;
using ESRI.ArcGIS.ADF.CATIDs;
using System.Runtime.InteropServices;

namespace sceneTools
{
  [ClassInterface(ClassInterfaceType.None)]
  [Guid("0FA87A1D-1C7E-4458-AE1C-DF85243A2793")]

  public sealed class TargetCenter : BaseTool
  {

        #region COM Registration Function(s)
        [ComRegisterFunction()]
        [ComVisible(false)]
        static void RegisterFunction(Type registerType)
        {
            // Required for ArcGIS Component Category Registrar support
            ArcGISCategoryRegistration(registerType);

            //
            // TODO: Add any COM registration code here
            //
        }

        [ComUnregisterFunction()]
        [ComVisible(false)]
        static void UnregisterFunction(Type registerType)
        {
            // Required for ArcGIS Component Category Registrar support
            ArcGISCategoryUnregistration(registerType);

            //
            // TODO: Add any COM unregistration code here
            //
        }

        #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 static void ArcGISCategoryRegistration(Type registerType)
        {
            string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
            ControlsCommands.Register(regKey);

        }
        /// <summary>
        /// Required method for ArcGIS Component Category unregistration -
        /// Do not modify the contents of this method with the code editor.
        /// </summary>
        private static void ArcGISCategoryUnregistration(Type registerType)
        {
            string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
            ControlsCommands.Unregister(regKey);

        }

        #endregion
        #endregion

    private System.Windows.Forms.Cursor m_pCursor;
    private ISceneHookHelper m_pSceneHookHelper;

    public TargetCenter()
    {
      base.m_category = "Sample_SceneControl(C#)";
      base.m_caption = "Target Center";
      base.m_toolTip = "Center on Target";
      base.m_name = "Sample_SceneControl(C#)/TargetCenter";
      base.m_message = "Center view at selected target";

      //Load resources
      string[] res = GetType().Assembly.GetManifestResourceNames();
      if(res.GetLength(0) > 0)
      {
        base.m_bitmap = new System.Drawing.Bitmap(GetType().Assembly.GetManifestResourceStream("sceneTools.TargetCenter.bmp"));
      }
      m_pCursor = new System.Windows.Forms.Cursor(GetType().Assembly.GetManifestResourceStream("sceneTools.targetcenter.cur"));
    
      m_pSceneHookHelper = new SceneHookHelperClass ();
    }

    public override bool Enabled
    {
      get
      {
        if(m_pSceneHookHelper.Scene == null)
          return false;
        else
          return true;
      }
    }
  
    public override void OnCreate(object hook)
    {
      m_pSceneHookHelper.Hook = hook;
    }
  
    public override int Cursor
    {
      get
      {
        return m_pCursor.Handle.ToInt32();
      }
    }
  
    public override bool Deactivate()
    {
      return true;
    }
  
    public override void OnMouseUp(int Button, int Shift, int X, int Y)
    {
      //Get the scene graph
      ISceneGraph pSceneGraph = (ISceneGraph) m_pSceneHookHelper.SceneGraph;

      IPoint pNewTgt;
      object pOwner, pObject;

      //Translate screen coordinates into a 3D point
      pSceneGraph.Locate(pSceneGraph.ActiveViewer, X, Y, esriScenePickMode.esriScenePickAll, true,
        out pNewTgt, out pOwner, out pObject);

      if(pNewTgt == null) return;

      //Get the scene viewer's camera
      ICamera pCamera = (ICamera) m_pSceneHookHelper.Camera;

      //If orthographic (2D) view
      if(pCamera.ProjectionType == esri3DProjectionType.esriOrthoProjection )
      {
        //Set the camera's new target
        pCamera.Target = pNewTgt;

        //Redraw the scene viewer
        pSceneGraph.ActiveViewer.Redraw(true);
      }
      else
      {
        //Get the camera's old target and observer
        IPoint pOldTgt, pOldObs;
        pOldTgt = pCamera.Target;
        pOldObs = pCamera.Observer;

        //Set the camera's new target and get the new observer
        pCamera.Target = pNewTgt;
        pCamera.PolarUpdate(1, 0, 0, true);

        IPoint pNewObs = (IPoint) pCamera.Observer;

        //Get the duration in seconds of last redraw
        //and the average number of frames per second
        double dlastFrameDuration, dMeanFrameRate;
        pSceneGraph.GetDrawingTimeInfo(out dlastFrameDuration, out dMeanFrameRate);
        
        if(dlastFrameDuration < 0.01)
          dlastFrameDuration = 0.01;

        int iSteps;
        iSteps = (int) (2 / dlastFrameDuration);
        if (iSteps < 1)
          iSteps = 1;

        if(iSteps > 60)
          iSteps = 60;

        double dxObs, dyObs, dzObs;
        double dxTgt, dyTgt, dzTgt;

        dxObs = (pNewObs.X - pOldObs.X) / iSteps;
        dyObs = (pNewObs.Y - pOldObs.Y) / iSteps;
        dzObs = (pNewObs.Z - pOldObs.Z) / iSteps;

        dxTgt = (pNewTgt.X - pOldTgt.X) / iSteps;
        dyTgt = (pNewTgt.Y - pOldTgt.Y) / iSteps;
        dzTgt = (pNewTgt.Z - pOldTgt.Z) / iSteps;

        //Loop through each step moving the camera's observer and target from the
        //old positions to the new positions, refreshing the scene viewer each time
        for(int i=0; i < iSteps; i++)
        {
          pNewObs.X = pOldObs.X + (i * dxObs);
          pNewObs.Y = pOldObs.Y + (i * dyObs);
          pNewObs.Z = pOldObs.Z + (i * dzObs);

          pNewTgt.X = pOldTgt.X + (i * dxTgt);
          pNewTgt.Y = pOldTgt.Y + (i * dyTgt);
          pNewTgt.Z = pOldTgt.Z + (i * dzTgt);

          pCamera.Observer = pNewObs;
          pCamera.Target = pNewTgt;
          pSceneGraph.ActiveViewer.Redraw(true);
        }
      }
    }
  }
}