[GDAL]在三维场景中显示DEM

合集 - GDAL(14)

1.ArcEngine和GDAL读写栅格数据机制对比（一）2013-10-18 2.[GDAL]1.GDAL1.8.1编译与第一个程序2012-12-12 3.C#+GDAL读取影像（1）2013-10-15 4.[GDAL]4.影像的读取和显示2012-12-31 5.[GDAL]3.影像金字塔构建2012-12-22 6.[GDAL]2.读取栅格和矢量数据2012-12-21 7.[GDAL]读取HDF格式的calipso数据2015-04-15 8.[GDAL]写入shp2015-04-02 9.ArcEngine和GDAL读写栅格数据机制对比（二）—— IPixelBlock读写栅格2014-11-11 10.[GDAL]GEOS和Proj4编译2014-03-29

11.[GDAL]在三维场景中显示DEM2014-02-16

12.[转载]C#下使用GDAL将dem转换为灰度图2014-02-16 13.[GDAL]编译64位GDAL1.102014-02-15 14.C#+GDAL读写文件2013-11-11

粗糙实现了个版本

存储波段的基本信息和数据：

 1 namespace RGeos.Terrain
 2 {
 3    //存储波段的基本信息和数据
 4     public class RasterBandData
 5     {
 6         public double[] data;
 7         public int Columns;
 8         public int Rows;
 9         public double NoDataValue;
10         public double MaxValue;
11         public double MinValue;
12     }
13 }

RasterBandData

显示用的渲染对象：

  1 using System;
  2 using RGeos.SlimScene.Core;
  3 using SlimDX.Direct3D9;
  4 using System.Drawing;
  5 using SlimDX;
  6 using CustomVertex;
  7 using System.IO;
  8 
  9 namespace RGeos.Terrain
 10 {
 11     public class RTerrain : RenderableObject
 12     {
 13         Device device = null;
 14         private Bitmap bitMap = null;
 15         private RasterBandData DataDem = null;
 16         //定义行列数目
 17         private int Cols = 5, Rows = 4;
 18         //定义像素的大小 
 19         private float cellHeight = 10f, cellWidth = 10f;
 20         //纹理
 21         private Texture texture = null;
 22         //材质
 23         private Material material;
 24         //顶点缓冲变量
 25         private VertexBuffer vertexBuffer;
 26         //索引缓冲变量
 27         private IndexBuffer indexBuffer;
 28         // 顶点变量
 29         private CustomVertex.PositionTextured[] vertices;
 30         //索引号变量
 31         private int[] indices;
 32 
 33         public RTerrain(string name, RasterBandData dem, Bitmap bitmap)
 34             : base(name)
 35         {
 36             DataDem = dem;
 37             Cols = dem.Columns;
 38             Rows = dem.Rows;
 39             bitMap = bitmap;
 40         }
 41 
 42         public override void Initialize(DrawArgs drawArgs)
 43         {
 44             try
 45             {
 46                 device = drawArgs.Device;
 47                 LoadTexturesAndMaterials();
 48                 VertexDeclaration();
 49                 IndicesDeclaration();//定义索引缓冲 
 50                 isInitialized = true;
 51             }
 52             catch (Exception ex)
 53             {
 54                 isInitialized = false;
 55                 throw ex;
 56             }
 57 
 58         }
 59         //导入贴图和材质
 60         private void LoadTexturesAndMaterials() 
 61         {
 62             material = new Material();
 63             material.Diffuse = Color.White;
 64             material.Specular = Color.LightGray;
 65             material.Power = 15.0F;
 66             device.Material = material;
 67             System.IO.MemoryStream memory = new System.IO.MemoryStream();
 68             bitMap.Save(memory, System.Drawing.Imaging.ImageFormat.Bmp);
 69             memory.Seek(0, SeekOrigin.Begin);
 70             texture = Texture.FromStream(device, memory);
 71         }
 72 
 73         public override void Update(DrawArgs drawArgs)
 74         {
 75             if (!isInitialized && isOn)
 76                 Initialize(drawArgs);
 77         }
 78         //定义顶点
 79         private void VertexDeclaration() 
 80         {
 81             vertexBuffer = new VertexBuffer(device, Cols * Rows * CustomVertex.PositionTextured.SizeBytes, Usage.Dynamic | Usage.WriteOnly, CustomVertex.PositionTextured.Format, Pool.Default);
 82             DataStream vs = vertexBuffer.Lock(0, Cols * Rows * CustomVertex.PositionTextured.SizeBytes, LockFlags.None);
 83             vertices = new CustomVertex.PositionTextured[Cols * Rows];//定义顶点 
 84 
 85             for (int i = 0; i < Rows; i++)
 86             {
 87                 for (int j = 0; j < Cols; j++)
 88                 {
 89                     //Color color = bitMap.GetPixel((int)(j * cellWidth), (int)(i * cellHeight));
 90                     float height = (float)DataDem.data[i * Cols + j];
 91                     if (height == DataDem.NoDataValue)
 92                     {
 93                         height = 0;
 94                     }
 95                     vertices[j + i * Cols].Position = new Vector3(j * cellWidth, height, -i * cellHeight);
 96                     vertices[j + i * Cols].Tu = (float)j / (Cols - 1);
 97                     vertices[j + i * Cols].Tv = (float)i / (Rows - 1);
 98                 }
 99             }
100             vs.WriteRange(vertices);
101             vertexBuffer.Unlock();
102             vs.Dispose();
103         }
104         //定义索引
105         private void IndicesDeclaration() 
106         {
107             indexBuffer = new IndexBuffer(device, 32 * 6 * (Cols - 1) * (Rows - 1), Usage.WriteOnly, Pool.Default, true);
108             DataStream ds = indexBuffer.Lock(0, 32 * 6 * (Cols - 1) * (Rows - 1), LockFlags.None);
109             indices = new int[6 * (Cols - 1) * (Rows - 1)];
110             int index = 0;
111             for (int i = 0; i < Rows - 1; i++)
112             {
113                 for (int j = 0; j < Cols - 1; j++)
114                 {
115                     indices[index] = j + i * (Cols);
116                     indices[index + 1] = j + (i + 1) * Cols;
117                     indices[index + 2] = j + i * Cols + 1;
118                     indices[index + 3] = j + i * Cols + 1;
119                     indices[index + 4] = j + (i + 1) * Cols;
120                     indices[index + 5] = j + (i + 1) * Cols + 1;
121                     index += 6;
122                 }
123             }
124             ds.WriteRange(indices);
125             indexBuffer.Unlock();
126             ds.Dispose();
127         }
128 
129         public override void Render(DrawArgs drawArgs)
130         {
131             if (!isInitialized || !isOn)
132                 return;
133             VertexFormat curFormat = drawArgs.Device.VertexFormat;
134             int curZEnable = drawArgs.Device.GetRenderState(RenderState.ZEnable);
135             int curLighting = drawArgs.Device.GetRenderState(RenderState.Lighting);
136             int curCull = drawArgs.Device.GetRenderState(RenderState.CullMode);
137             int curAlphaBlendEnable = drawArgs.Device.GetRenderState(RenderState.AlphaBlendEnable);
138             int curDepthBias = drawArgs.Device.GetRenderState(RenderState.DepthBias);
139             int curColorOperation = drawArgs.Device.GetTextureStageState(0, TextureStage.ColorOperation);
140             try
141             {
142                 drawArgs.Device.SetRenderState(RenderState.Lighting, false);
143              drawArgs.Device.VertexFormat = PositionTextured.Format;
144                 drawArgs.Device.SetRenderState(RenderState.ZEnable, true);
145                 drawArgs.Device.SetRenderState(RenderState.CullMode, Cull.None);
146                 drawArgs.Device.SetTextureStageState(0, TextureStage.ColorOperation, TextureOperation.Modulate);
147                 drawArgs.Device.SetTextureStageState(0, TextureStage.ColorArg1, TextureArgument.Texture);
148                 drawArgs.Device.SetTextureStageState(0, TextureStage.ColorArg2, TextureArgument.Diffuse);
149                 drawArgs.Device.SetTextureStageState(0, TextureStage.AlphaOperation, TextureOperation.Disable);
150                 device.SetTexture(0, texture);//设置贴图 
151 
152                 device.SetStreamSource(0, vertexBuffer, 0, PositionTextured.SizeBytes);
153                 device.Indices = indexBuffer;
154                 device.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, (Cols * Rows), 0, indices.Length / 3);
155             }
156             catch (Exception ex)
157             {     
158             }
159             finally
160             {
161                 drawArgs.Device.VertexFormat = curFormat;
162                 drawArgs.Device.SetRenderState(RenderState.ZEnable, curZEnable);
163                 drawArgs.Device.SetRenderState(RenderState.Lighting, curLighting);
164                 drawArgs.Device.SetRenderState(RenderState.CullMode, curCull);
165                 drawArgs.Device.SetRenderState(RenderState.AlphaBlendEnable, curAlphaBlendEnable);
166                 drawArgs.Device.SetRenderState(RenderState.DepthBias, curDepthBias);
167                 drawArgs.Device.SetTextureStageState(0, TextureStage.ColorOperation, curColorOperation);
168             }
169         }
170 
171         public override void Dispose()
172         {
173             if (vertexBuffer != null)
174             {
175                 vertexBuffer.Dispose();
176                 vertexBuffer = null;
177                 texture = null;
178                 vertices = null;
179             }
180             if (indexBuffer != null)
181             {
182                 indexBuffer.Dispose();
183                 indexBuffer = null;
184                 indices = null;
185             }
186         }
187 
188         public override bool PerformSelectionAction(DrawArgs drawArgs)
189         {
190             throw new NotImplementedException();
191         }
192     }
193 }

RTerrain

调用方法：

 1   OpenFileDialog dlg = new OpenFileDialog();
 2             dlg.Title = "";
 3             dlg.Filter = "Img(*.img)|*.img";
 4             if (dlg.ShowDialog() == DialogResult.OK)
 5             {
 6                 string file = dlg.FileName;
 7                 string NameOf = System.IO.Path.GetFileNameWithoutExtension(file);
 8                 DemHelper dem = new DemHelper();
 9                 dem.Start();
10                 dem.Read(file);
11                 RasterBandData bandata = dem.ReadDate(50, 40);
12                 Bitmap bitmap = dem.MakeGrayScale(50, 40);
13                 Vector3 position = new Vector3(-100f, 0f, 100f);
14                 //SimpleRasterShow simRaster = new SimpleRasterShow(NameOf, position, bitmap.Width, bitmap.Height);
15                 //simRaster.IsOn = true;
16                 //simRaster.RenderPriority = RenderPriority.Custom;
17                 //simRaster.bitmap = bitmap;
18                 //mSceneControl.CurrentWorld.RenderableObjects.ChildObjects.Add(simRaster);
19                 RTerrain terrain = new RTerrain(NameOf, bandata, bitmap);
20                 terrain.IsOn = true;
21                 mSceneControl.CurrentWorld.RenderableObjects.ChildObjects.Add(terrain);
22             }