Integration of my own elevation file..

[mertk]

Hi all developer team;

I have a question about plugging my own elevation to WWJ. I surveyed this forum before. I see some approaches on that issue. However, I cannot meet efficient and real solution.

Firstly, I have a elevation file in DTED, DEM, JP2 or TIF formats. After my research in forum, I've decided to create tiles of my elevation file. I perform this operation with Global Mapper 9 at 13 level detail and saving with .jpg extension. The folder name is formed like this: 0->0364->0364_0588.jpg, 1->0728->0728_1177.jpg bla bla.. I've read tiling system of WW. It creates tiles with row and column numbers (e.g 0_8.dds). But I am not sure for my tiling. How can I integrate my own tiles to the WWJ. Is it sufficient to see my own elevation in WW application? And also if my tiling way is wrong, how can i correct it?

Then, because of my failure in tiling, I tried something about .bil files. I can convert my elevation file to the .bil files in 150x150 resolution with Global Mapper 9 too. That program also create a xml file for my elevation file. I looked at geodan's walktrough example. This example is developed for .net version of WW. But I can't find Earth subfolder under Config folder in WWJ source which I will put xml file which Global Mapper creates. So I don't understand how i integrate elevations from my bil file to the WWJ. Anybody know it?

My last question: for plugging my own elevation from my elevation file in WWJ, what is the way to follow? Is it possible to implement it? My sayings in above are logical? I am very new in WW. But answers of these questions is vital for me since using them in my Senior Project and also time is limited..

Thanks for advance..

[mertk]

I wish saying someting more about converting my elevation file to bil files. I am able to converting it like only one .bil file. I see exteme elevation under the config folder with the name SRTM30Plus_ExtremeElevations_2.bil. Is it logical replace this file with my single bil file. Moreover, can i add my single bil file to the cache and load from it like extreme elevation bil file? Can i see the elevations in application with this way at the end?

Thank you again..

[patmurris]

Elevations are tiled into 150x150x16 bits .bil files over a number of 'levels' for both WW.net and WWJ.

However, there is no way to patch a specific portion of elevation data over the base SRTM30Plus in WWJ - you can do it in WW.net though.

On approach is to tile you own data exactly the same way as WWJ expects it and place it in WWJ cache folder (WorldWindData/Earth/srtm30pluszip) so that it will use your data instead of downloading the SRTM ones. This is a bit tricky though as you have to match exactly the expected grid/levels.

You can find information about what WWJ expects for elevation data in globes.EarthElevationModel: 150x150 tiles, level zero tile size: 20 degrees, 10 levels, full sphere.

Integrating your own elevation data into WWJ is being worked on right now and will probably be available in the next release.

[mertk]

Thank you patmurris. I'll try it.

As I said before, I use Global Mapper 9 for bil tiling operations. I want to be sure about that. I write down respectively my job done with the program:

First, Export Raster and Elevation Data->Export BIL/BIP/BSQ file
Then I choose "Elevation 2 Bytes (16 bits) per Sample" for format from options menu
and then I pass Gridding label. I choose "Specify Individual Grid Cell Width and Height". I give the same arc degree "0.01953125"(20/2^10) for width and height. However, I don't understand grid naming exactly. I think it cannot match WW tile naming. What is your opinion? How can i do that? Anybody know that program using? If I perform tiling operations like that, can I meet my requirements? : 150x150x16 tiles, level zero tile size: 20 degrees, 10 levels, full sphere. If Global Mapper is wrong program for bil tiling, is there any another program you advice me for converting operation?

Thanks..

[nlneilson]

http://www.worldwindcentral.com/wiki...to#Custom_DEMs

[Hervé]

Hi Merkt,

A note about Global Mapper: it uses the old WW.Net tile naming. So to use the tileset produced by Global Mapper with WWJ you will have to remove the leading zeroes in the file names, eg "3/0472/0472_0013.bil" becomes "3/472/472_13.bil".

Now on my own experience: I managed to successfully use my own very high resolution terrain into WWJ by simply producing tiles as they are expected by WW, adding my levels to next the default ones (0 to 8 if I remember) into the "srtm30pluszip" folder.

I did not use Global Mapper for this, but a simple converter coded in Java, as it was not as tricky as Pat Murris pretends ;-) It is just a quadtree after all.

However I had to modify a few classes, as the tile level limit was hardcoded (well at least it was with version 4.1, it may have changed though). Else no matter how much I zoomed, it would never switch to my high resolution levels.