One of the more complex problems in SC has been the rules by which spirit houses spawn. Several possibilities have been proposed, but now we have an answer. Raelyne and I spent a few days doing some research involving dom leapfrogging, driving and walking, and here's what we found:

Spirit houses spawn according to where YOU are on a simple grid system. This is the first point that causes confusion. What matters is not where the spirits spawn, but where you are to spawn them:
* Inriks are north and south of Dannans.
* Drioma are north and south of Tiermes.
* Tiermes and east and west of Inriks.
* Drioma are east and west of Dannans.



We think several things have contributed to the confusion. For one, the division between houses is very precise. When you are on a cusp, walking across the street or into a different room of the house will spawn the other house. People do not realize the magnitude of the error when warping to an object, or the inherent slop in GPS. You never spawn more than one house per location, but you may well warp around an object and end up in a different house. These areas do not appear to change. For instance, your Dannan spot does not become a Drioma spawn, but you may be just across the border. Also, you could be within sight (often are) of another mage who is in a different house. You will see a combination of the spirits she spawns and the ones you spawn, which can be confusing. Lastly, we tend to think in terms of geography which rarely runs truly NSEW, so this may further obscure what is a very simple pattern.

Doing this research in NYC and London, we found that the grids for houses are rectangles approximately 1,900 tall by 2,500 feet wide. However, we noticed a very slight curvature to the lines on the map, which is almost certainly a reflection of the curvature of the earth. (The shortest distance between two points on the earth *is* a straight line, but it's a line that goes under the surface of the earth. The shortest distance between two points on a map is actually an arc.) It is also interesting to note that these grids appear to be very close to 16 minutes of longitude by 32 minutes of latitude. Though this was not verified at other spots on the globe, it seems pretty likely that everything in SC scales like this.

So... that's it. And it's kind of sad to post this because this was, to me, one of the last and thorniest problems in SC... I kinda feel like we've answered the questions. If you want more geekery, here are our research maps. We verified at other points as well, but this is just what we recorded.

Map with spirit houses by color:


Grid added:


Map removed to highlight grid:



Raelyne's map:

Edited by GiantDong (Nov. 6, 2011 04:45:55)

Reserved for more info

Such a bittersweet moment . . .

absolutely stunning. Cheers to Shadow Cities for the design and to my teammates for figuring it out.

Nice work! While I haven't done extensive confirmation, this appears to match my experiences in my spawns. It would appear the grid is roughly 1 KM squares? Fits with my notion that the shadow line is roughly 1 KM and the harvest range is roughly 2 KM.

Edited by SerottaCSi (Nov. 6, 2011 00:00:46)

The grid being 'squashed' in that manner is interesting to me.

Bardfinn
The grid being 'squashed' in that manner is interesting to me.

The shadow line appears to be less than circular, possibly a rounded version of the same shape?

interesting... yeah we can do that one too... stay tuned

SerottaCSi
The shadow line appears to be less than circular, possibly a rounded version of the same shape?

Gabriel
GD, Raelyne, I've already praised this (well, to GD, at least), but well done! Do you mind if I link from the info thread?

sure. link away!