So that post on Megaregions ended up being a bit more popular than I imagined – resulting in a veritable torrent of ‘How do I enable megaregions?‘ requests both to my personal inbox, the #opensim-dev chatroom and the opensim-dev mailing lists. You can stop now. Here’s instructions.

It’s actually really simple if you are running the latest experimental code, however I need to prefix these instructions with a dire warning: this is very new code. The first prototype was done on August 28th.  It’s been a week and a half since then. Yes MegaRegions are an exciting bit of technology, but no – they are not that well tested, and yes there are bugs. More than usual. It was added to OpenSim as a undocumented feature because Teravus (in his right mind) didnt want to inflict it on the masses until it had at least a modicum of testing among more experienced users.

There are known issues at this stage – do not attempt to convert an existing array of regions into a single Megaregion without taking a full backup first (apparently there are issues there too) – if you still want to go ahead and check this out; you need to be running a relatively recent Git release of OpenSim (warning: there be dragons here already), into your OpenSim.ini add the line “CombineContiguousRegions=true” under the [Startup] section, eg:

[Startup]
CombineContiguousRegions=true
...

The regions need to be contiguous (that is already bordering), and you need to order the regions in your Regions.ini in a Left-to-Right, Top-to-Bottom (Correction: South-to-North, West-to-East) order. Failing to order the regions will cause the combiner to fail (new code. known issues.); it is recommended to make new regions for the purpose of this exercise. Otherwise, this is a fairly simple process to those already aquainted with setting up OpenSim regions. Credit goes to Teravus for the original implementation.

Grid etiquette right now suggests it is best to not connect megaregions neighbouring to non-megaregions for the moment, as they may introduce instabilities into your neighbours. (eg, pick random numbers for your starting coordinates). While you can connect megaregions to grids such as OSgrid, please do so away from the main continents. For loading a terrain across all the regions, I recommend investigating the “terrain load-tile” command, which allows you to import multiple regions worth of terrain from a single image. The above terrain was generated off a 2048×2048 F32 RAW produced by World Machine.