SceneControl中如何设置矢量图层按DEM起伏显示？

【解决办法】：
Engine中首先要获取该矢量图层的I3DProperties接口，然后设置I3DProperties.BaseOption为esriBaseSurface，并且I3DProperties.BaseSurface指定为该DEM即可，参考代码：

ISceneGraph scenegraph = axSceneControl1.SceneGraph;

             IScene scene = scenegraph.Scene;

             ILayer layer = scene.get_Layer(0);

             IRasterLayer rasterLayer = scene.get_Layer(1) as IRasterLayer;

             IRaster raster = (IRaster)rasterLayer.Raster;



             IRasterBandCollection rasterbands = raster as IRasterBandCollection;

             IRasterBand rasterband = rasterbands.Item(0);



             IRasterSurface rasterSurface = new RasterSurface();

             rasterSurface.RasterBand = rasterband;          



             I3DProperties p3DProps = Get3DPropsFromLayer(layer) as I3DProperties;

             if (p3DProps != null)

             {

                                

                 p3DProps.BaseOption = esriBaseOption.esriBaseSurface;

                 p3DProps.BaseSurface = rasterSurface as IFunctionalSurface;

                 p3DProps.ZFactor = 2;

                 p3DProps.Apply3DProperties(layer);

                 axSceneControl1.SceneGraph.RefreshViewers();

             }



public I3DProperties Get3DPropsFromLayer(ILayer pLayer)

        {

            I3DProperties p3DProps = null;

            try

            {

                ILayerExtensions pExt = pLayer as ILayerExtensions;

              

                for (int i = 0; i < pExt.ExtensionCount; i++)

                {

                    if (pExt.get_Extension(i) is I3DProperties)

                    {

                        p3DProps = (I3DProperties)pExt.get_Extension(i);

                    }



                }

                if (p3DProps == null) Trace.WriteLine(未能获取图层的I3DProperties接口。);

                return p3DProps;

            }

            catch (Exception ex)

            {

                Trace.WriteLine(获取图层的I3DProperties接口时发生异常 + ex.ToString());

                return null;

            }

        }