[OpenLayers-Dev] Re: Day and night shadow map

[Peter Körner]

Hi

Am 20.06.2011 12:40, schrieb Fixdit:
> The input is very much appreciated,
> I'm kind of new to Open Layers and feeling my way around. How would I
> generate the curve? Via a mask or a would this be incorporated into the
> images pre render?

Talking about how daylightmap.com did it, I guess they're using a 
shapefile or a postgis-db that holds an approximation of that curve. I 
don't think, they calculate the shape just-in-time.

Additionally they likely have some data-source for the lighting part 
(eg. http://apod.nasa.gov/apod/ap001127.html, see: 
http://apod.nasa.gov/apod/image/0011/earthlights2_dmsp_big.jpg)

Those two sources are combined at the server side into one image, 
possibly using some WMS or some Tile-Server infratructure 
(Tirex/Mapnik), producing those tiled images: 
http://www.daylightmap.com/tiles/cache/tile_n_3_0_2_1308564480.png

If you want it Changing by time, You need one pre-rendered tile per hour.

Peter