Managed DirectX (MDX)鼠标选取Mesh的一个区域

#region 依射线 选中Mesh的一个区域 /// /// 依射线 选中Mesh的一个区域 /// /// 射线的横坐标 /// 射线的纵坐标 /// 选中区域序号

public int PickArea(int para_iX, int para_iY) {

// 由横纵坐标产生选取射线

Vector3 nearVector = new Vector3(para_iX, para_iY, 0);

Vector3 farVector = new Vector3(para_iX, para_iY, 1);

//device.Transform.World = ((CLoadXFile)g_arrayListX[i]).meshWorld;

nearVector.Unproject(device.Viewport, device.Transform.Projection, device.Transform.View, device.Transform.World); farVector.Unproject(device.Viewport, device.Transform.Projection, device.Transform.View, device.Transform.World); farVector.Subtract(nearVector);

IntersectInformation closetHit = new IntersectInformation();

bool bIntersect = mesh.Intersect(nearVector, farVector, out closetHit);

if (!bIntersect) {

  return -1;

}

AttributeRange[] ar = mesh.GetAttributeTable();

int iNumberArea = -1;

int iFaceIdx = closetHit.FaceIndex;

for (int j = 0; j < ar.Length; j++) {

   if (iFaceIdx >= ar[j].FaceStart) {

      if (iFaceIdx <= ar[j].FaceStart + ar[j].FaceCount - 1) {

        iNumberArea = j; break;

  }

}

}

return iNumberArea;

}

#endregion