[GDAL]在三维场景中显示DEM
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 }
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 }
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 }