importing-heightmaps-from-gdex.md

Importing GDEX data into Unity

1. Export data from GDEX (Global Data Explorer) (https://gdex.cr.usgs.gov/gdex/)

2. Apply levels to data to make it a bit 'shorter'

3. Save the image as a bitmap.

4. Convert the bitmap to a RAW image

   /// <summary>
   /// Convert a bitmap to a byte array
   /// </summary>
   /// <param name="bitmap">image to convert</param>
   /// <returns>image as bytes</returns>
   private static byte[] ConvertBitmapToRaw(Bitmap bitmap)
   {
       //Code excerpted from Microsoft Robotics Studio v1.5
       BitmapData raw = null;  //used to get attributes of the image
       byte[] rawImage = null; //the image as a byte[]
   
       try
       {
           //Freeze the image in memory
           raw = bitmap.LockBits(
               new Rectangle(0, 0, (int)bitmap.Width, (int)bitmap.Height),
               ImageLockMode.ReadOnly,
               PixelFormat.Format8bppIndexed
           );
   
           int size = raw.Height * raw.Width;
           rawImage = new byte[size];
   
           int rem = raw.Width % 4;
           int padding = rem == 0 ? 0 : 4 - rem;
   
           int basePtr = raw.Scan0.ToInt32();
           //Copy the image into the byte[]
           for (int r = 0; r < raw.Height; r++)
           {
               int srcOffset = r * (raw.Width + padding);
               int dstOffset = r * raw.Width;
               Marshal.Copy(new IntPtr(basePtr + srcOffset), rawImage, dstOffset, raw.Width);
           }
       }
       finally
       {
           if (raw != null)
           {
               //Unfreeze the memory for the image
               bitmap.UnlockBits(raw);
           }
       }
       return rawImage;
   }

5. Import the RAW image into Unity.

   • It should detect the settings.

6. Download GoogleMaps data for the given area.