Merci beaucoup !!!
Well, i can try to give more details about these projects but you know, i’m french and i don’t speak and write very well english.
So , i understand you talk about 1st link
This project was the first one i’ve made about topography.
I work for a museum, i’m in charge of multimedia.
The museum is about ww1.
In ww1, lot of battles in differents locations.
The topography of the battlefields have a very high importance in the strategy, human losses, …
Educational service (teachers in the museum), guides, historical services, historians, … who works in the museum ask me to find a way to display terrains and trench maps in 3D.
I can’t use a tool or an API to do it. (if the users conditions change, if it’s free at beginning and change after, …) I have to stay independant.
My annual budget is 0. (in Euro, Dollars or Yen, as you want).
My job is at half-time.
And i have to find something who work well, in a minimum of time, and someone must be able to replace me.
It’s why i have choosen to use three.js (Quick, efficient, flexible, …)
It’s very important to understand This project don’t use an height-map to construct geometry.
Why don’t use height-map bitmap ?
Because i want to have accuracy and a good link between each tiles of the map. You can test with an height-map bitmap, it’s not really good. Links between each tiles are really bads.
(i said a tile, but in three.js it’s PlaneGeometry)
It use Esri ASCII data. SRTM Data – CGIAR-CSI SRTM
Look this site to have an exemple, files must be .asc
Data are numbers. Each number correspond to an elevation of the ground at a location (a latitude and a longitude).
And i can easily put these numbers in a server and deform the mesh
With numbers (elevation) and a link to a location (lat,lon) , stored in a server, i can play with.
The idea was
1 PlaneGeometry, with 9 widthSegments and 9 heightSegments give me a mesh with 100 nodes.
Each node of the mesh represent a location, so i can deform all nodes in Z to generate the relief.
It’s not heavy, and i have a perfect link between all tiles.
Why lot of tiles and not a big one tile ?
If i want to move on a map, i’m limited by the size of the map, and if i want to generate a new part of the terrain, i have to wait a lot of data (server asked with ajax)
But with a grid, made with 10 x 10 PlaneGeometry ( or 12 x 20, …) , and each PlaneGeometry have
9 widthSegments and 9 heightSegments, if i move in the North, i can append new tiles in the North, and delete some tiles in the South.
It’s light, quick because small tiles load small textures images quickly.
I can explain more but i didn’t know if you want more informations.