/// <summary>

        /// 叠加DEM

        /// </summary>

        /// <param name="pRasterLayer">DEM栅格</param>

        /// <param name="pOutRastLay">影像栅格</param>

        private void SufraceDEM(IRasterLayer pRasterLayer, IRasterLayer pOutRastLay)

        {

            IRasterSurface pRasterSurface = new RasterSurface();

            pRasterSurface.PutRaster(pRasterLayer.Raster, );

            ISurface pSurface = pRasterSurface as ISurface;

            ILayerExtensions pLayExtensions = pOutRastLay as ILayerExtensions;

            I3DProperties p3DProperties = null;

            for (int i = ; i < pLayExtensions.ExtensionCount; i++)

            {

                if (pLayExtensions.get_Extension(i) is I3DProperties)

                {

                    p3DProperties = pLayExtensions.get_Extension(i) as I3DProperties;

                }

            }

            p3DProperties.ZFactor =; //夸张系数

            p3DProperties.BaseOption = esriBaseOption.esriBaseSurface;

            p3DProperties.BaseSurface = pSurface;

            p3DProperties.Apply3DProperties(pOutRastLay);

        }

 ILayer pLayer = getLayerByname("dem_project.tif");

 IRasterLayer pDemRasterLayer = pLayer as IRasterLayer;

 ILayer pImgLayer = getLayerByname("sx_img_3857.tif");

 IRasterLayer pImgRasterLayer = pImgLayer as IRasterLayer;

 SufraceDEM(pDemRasterLayer, pImgRasterLayer);

 axSceneControl1.SceneGraph.RefreshViewers();

    /// <summary>

        /// 获取指定图层通过名称

        /// </summary>

        private ILayer getLayerByname(String name)

        {

            ILayer layer = null;

            int count = axSceneControl1.Scene.LayerCount;

            if (count == ) MessageBox.Show("请加载图层");

            for (int i = ; i < count; i++)

            {

                layer = axSceneControl1.Scene.get_Layer(i);

                if (name == layer.Name.ToString())

                {

                    break;

                }

            }

            return layer;

        }

       /// <summary>

        /// 叠加TIN

        /// </summary>

        private void AddTINSufrace(IRasterLayer pOutRastLay, ITin tin)

        {

            ITinAdvanced pTINAdvanced = tin as ITinAdvanced;

            ISurface pSurface = pTINAdvanced.Surface;

            ILayerExtensions pLayExtensions = pOutRastLay as ILayerExtensions;

            I3DProperties p3DProperties = null;

            for (int i = ; i < pLayExtensions.ExtensionCount; i++)

            {

                if (pLayExtensions.get_Extension(i) is I3DProperties)

                {

                    p3DProperties = pLayExtensions.get_Extension(i) as I3DProperties;

                }

            }

            p3DProperties.ZFactor =;

            p3DProperties.BaseOption = esriBaseOption.esriBaseSurface;

            p3DProperties.BaseSurface = pSurface;

            p3DProperties.Apply3DProperties(pOutRastLay);

        }

ILayer layer = getLayerByname("Tin");

ITinLayer tinlayer = layer as ITinLayer;

ILayer pImgLayer = getLayerByname("sx_img_3857.tif");

IRasterLayer pImgRasterLayer = pImgLayer as IRasterLayer;

AddTINSufrace(pImgRasterLayer, tinlayer.Dataset);