Sunday, 12 August 2007

Loch Avie and the Terrain Disaster

Nicholas K, Bellambi E. Unexpected loss of terrain data in a Caledon duchy. Proc Royal Soc 2007;8.

Caledon Loch Avie suffered a data casualty on Friday, August 10, during a period of ongoing unusual server performance. One of the authors (EB) witnessed a whole-scale disruption in the Loch Avie terrain. Land elevations were affected across the sim, with some locations receeding over 1 metre. Three woman-hours of terraforming was required to return the Loch's landscaping to normal.

While the reader is likely familiar with the typical SL behaviour after client updates and on busy weekend times, the usual set of errors has not, to date, concerned sim structure, but rather, the classic shoe-bum attachment and loss of inventory.

After an uneventful period in-game, EB discovered that across the Loch, terrain elevations had been altered. Land permissions had not been changed, and were re-confirmed to have public terraforming disabled. A check of the estate tools revealed no change to the sim-wide water level, or terrain features.

The damage consisted of widespread lowering of certain -- but not all -- locations in the loch, and affected both the major land division (Loch Avie proper) as well as the Inbhir Abigh ("Inveravie") sub-parcel at the southwest corner.

The most obvious indicators of a change in terrain were objects now above the ground level which once were at ground level. More subtle changes involved ground on the railroad tracks, and changes in shape to the mountains.

Approximately three hours of terraforming was required to return the Loch to the closest pre-event state possible. The 'revert' land tool proved very useful, though there were significant differences in pre-event and original terrain due to two duchesses' worth of ownership.

Caledon Loch Avie's terrain was diffusely changed by an unknown mechanism. Repairing the damage was made easier by using the land reversion tool, and by looking at objects to gauge the amount of change that had occurred. Sim owners could increase the ease of terrain recovery by using the terrain data file upload and download features in the estate menu (though neither author has any experience with such). Sim rollback would be another, if drastic, option to investigate.

The cause of the mishap is unknown. Given the fact that the simulator terrain data is an integral part of the sim, and not under the control of the asset server, such a fault would suggest something amiss with the computer on which Loch Avie is simulated, and not a client-side or asset server-side problem.

The Society will continue to serve as a clearinghouse for any future information on such events. Readers are invited to share any information as it may become available.


HeadBurro Antfarm said...

Fig. 5 is better than the state of most British railways :)

Edward Pearse said...

I would be curious if the phenomenon is confined to the Loch Avie Duchy or whether it was more widespread.

Baron K. Wulfenbach said...

I remembered seeing this report as I was walking Juntarou widdershins just now. Although in front of that boarded-up building one would expect weedy intrusions between the pavers, just a little further on I found a large grassy lump poking up right in front of the library.

Could this be the symptom of a smaller-scale version of the phenomenon?

Yrs, KW