public void DEMToTIN(IRaster iRaster, string tinFileName)
{
try
{
//***************生成TIN模型*********************************************
IGeoDataset pGeoData = iRaster as IGeoDataset;
IEnvelope pExtent = pGeoData.Extent;
IRasterBandCollection pRasBC = iRaster as IRasterBandCollection;
IRasterBand pRasBand = pRasBC.Item(0);
IRawPixels pRawPixels = pRasBand as IRawPixels;
IRasterProps pProps = pRawPixels as IRasterProps;
int iWid = pProps.Width;
int iHei = pProps.Height;
double w = iWid / 1000.0f;
double h = iHei / 1000.0f;
IPnt pBlockSize = new DblPntClass();
bool IterationFlag;
if (w < 1 && h < 1) //横纵都小于1000个像素
{
pBlockSize.X = iWid;
pBlockSize.Y = iHei;
IterationFlag = false;
}
else
{
pBlockSize.X = 1001.0f;
pBlockSize.Y = 1001.0f;
IterationFlag = true;
}
double cellsize = 0.0f; //栅格大小
IPnt pPnt1 = pProps.MeanCellSize(); //栅格平均大小
cellsize = pPnt1.X;
ITinEdit pTinEdit = new TinClass() as ITinEdit;
pTinEdit.InitNew(pExtent);
ISpatialReference pSpatial = pGeoData.SpatialReference;
pExtent.SpatialReference = pSpatial;
IPnt pOrigin = new DblPntClass();
IPnt pPixelBlockOrigin = new DblPntClass();
//栅格左上角像素中心坐标
double bX = pBlockSize.X;
double bY = pBlockSize.Y;
pBlockSize.SetCoords(bX, bY);
IPixelBlock pPixelBlock = pRawPixels.CreatePixelBlock(pBlockSize);
object nodata = pProps.NoDataValue; //无值标记
ITinAdvanced2 pTinNodeCount = pTinEdit as ITinAdvanced2;
int nodeCount = pTinNodeCount.NodeCount;
object vtMissing = Type.Missing;
object vPixels = null; //格子
double m_zTolerance = 0;
if (!IterationFlag) //当为一个处理单元格子时;(w < 1 && h < 1) //横纵都小于1000个像素
{
pPixelBlockOrigin.SetCoords(0.0f, 0.0f);
pRawPixels.Read(pPixelBlockOrigin, pPixelBlock);
vPixels = pPixelBlock.get_SafeArray(0);
double xMin = pExtent.XMin;
double yMax = pExtent.YMax;
pOrigin.X = xMin + cellsize / 2;
pOrigin.Y = yMax - cellsize / 2;
bX = pOrigin.X;
bY = pOrigin.Y;
pTinEdit.AddFromPixelBlock(bX, bY, cellsize, cellsize, nodata, vPixels, m_zTolerance, ref vtMissing, out vtMissing);
}
else //当有多个处理单元格时，依次循环处理每个单元格
{
int i = 0, j = 0, count = 0;
int FirstGoNodeCount = 0;
//while (nodeCount != FirstGoNodeCount)
//{
count++;
nodeCount = pTinNodeCount.NodeCount;
int bwidth = 0; int bheight = 0;
//依次循环处理
for (i = 0; i < (int)h + 1; i++)
{
if (i < (int)h)
{
bheight = 1000;
}
else
{
bheight = iHei - 1000 * i;
}
for (j = 0; j < (int)w + 1; j++)
{
if (j < (int)w)
{
bwidth = 1000;
}
else
{
bwidth = iWid - 1000 * j;
}
pBlockSize.SetCoords(bwidth, bheight);
pPixelBlock = pRawPixels.CreatePixelBlock(pBlockSize);
double bX1, bY1, xMin1, yMax1;
bX1 = pBlockSize.X;
bY1 = pBlockSize.Y;
pPixelBlockOrigin.SetCoords(j * 1000, i * 1000);
pRawPixels.Read(pPixelBlockOrigin, pPixelBlock);
vPixels = pPixelBlock.get_SafeArray(0);
xMin1 = pExtent.XMin;
yMax1 = pExtent.YMax;
//bX1 = pBlockSize.X;
//bY1 = pBlockSize.Y;
pOrigin.X = xMin1 + j * 1000 * cellsize + cellsize / 2.0f;
pOrigin.Y = yMax1 - i * 1000 * cellsize - cellsize / 2.0f;
bX1 = pOrigin.X;
bY1 = pOrigin.Y;
pTinEdit.AddFromPixelBlock(bX1, bY1, cellsize, cellsize, nodata, vPixels, m_zTolerance, ref vtMissing, out vtMissing);
FirstGoNodeCount = pTinNodeCount.NodeCount;
}
}
//}
}
//保存TIN文件
pTinEdit.SaveAs(tinFileName, ref vtMissing);
pTinEdit.StopEditing(true);
m_pTin = pTinEdit as ITin;
MessageBox.Show("转换成功！");
}
catch (SystemException e)
{
MessageBox.Show(e.Message);
}
}