Coordinates are a very good way to define the position of an object in space or a Geographic place on map. Please note that among Second Life there are two types of coordinates: sim coordinates and grid coordinates.
Sim Coordinates Edit
They are used to show position of an object or an avatar within a sim. You can see them while editing an object or on land description, on top-left of your viewer. Coordinates are composed of 3 vlues: X (longitude), y (latitude) and z (altitude). Values are in meters.
Each sim in Second Life is 256 meters long and 256 meters wide. So, at the South-west corner, values for X and Y are 0, 0. The third coordinate, z, defines altitude. There are no negative altitudes. Lowest possible level is 0. Water surface is usually set at 20 meters high, but this is not a rule. For ground surface, Altitude varies from 0 to a maximum of 389 meters in Castle Bella (Campion sim), Mountains Of Heterocera. However, in many places, objects can exist in skyboxes, at far greater altitudes, up to 4096 meters. Building above 4096 is not possible, but avatars can fly even higher then 5000 meters, where they find the sky limit.
The llGetPos function gives sim coordinates.
Grid Coordinates Edit
It is possible to define position of any object on the map. llGetRegionCorner gives the global position of a point placed at sim coordinates (0, 0, 0). By combining this function with llGetPos, you can get current grid position of an object.
Map Coordinates Edit
Grid coordinates are hard to handle, since they are in meters. They look like this:
<256359, 2565748, 528> <345258, 2464876, 487> <284568, 6584754, 126>
In practice, while defining position of a sim, altitude is useless, so only x and y are shown. And also, since a sim is 256/256 meters, by dividing x and y to 256 and rounding the values, you get map coordinates. Map coordinates are the following ones:
(858, 1440) (1012-1004) (1022/749)
The format is not important, what is important is to display first the longitude and second the latitude.
When defining a larger grid structure, with many sims, first are listed the maximum and minimum longitude values, then the maximum and minimum for latitude, separated by a slash. Coordinates will look like this:
587-592/1024-1123 1022-1027/1104-1135 1099-1134/787-798
The oldest sim on the grid, Da Boom, is placed at coordinates 1000/1000. In old times, its coordinates were 0/0, meaning that also negative values existed. Currently, there are only positive values. There are no places with coordinates further then 1999/1999.
See Also Edit
- Second Life Geography
- List Of Microcontinents And Sim Clusters
- List Of Grid Sectors
- Grid Map And Dimensions