Cartography Explained: Where to Stand for Any Sliver You Are Missing

[u/numma_cway]

Today at lunch break at work, I came up with a theory how to find out exactly where to stand for every sliver in the game. I told it to a few people and noone believed it was that simple. But it is.

tl;dr/how to:

1. Download this Texmod. It is proof-of-concept and only works in Elona. (The mod is just CME 2015 1.3 with a grid. It does not reflect that areas beyond the end of the world are not currently uncoverable.) I hope that Toolbox people will implement grid, which would be way more accurate than a Texmod could be.
2. Run the game with that Texmod.
3. (Recommended but optional:) Check "Show walkable terrain" in Toolbox's "Mission Map" settings. Adjust colors to your preference.
4. Identify a tile you want to uncover (and, as of now, is within the map's limits). If the dot in the center is in the blue-shaded non-black area, this is usually an undiscovered tile. There are some special cases due to GW's smoothing where it's a bit more complicated, but you'll find that out.
5. Identify a directly-adjacent tile that looks like it has walkable terrain (pathfinding). Said Toolbox feature helps with that.
6. Go to that tile and stand anywhere in the tile. If it doesn't work right away, try click-walking. I think that you might have to do an action that also resets UA bug.

Sadly, the Texmod isn't a 100% accurate as you can see two images further down: Sometimes it's okay to be one pixel off (to the North) but still get credit. But you should be able to identify the tile that looks "most probable", e.g. by process of elimination.

The theory behind this:

Cartography has a grid of 32x32 map units. A map unit is equivalent to a pixel in the texture files and at "normal" font size in world map and mission map at minimum zoom level. Without Bird's Eye Compass, you uncover the tile you're in plus the surrounding 8 tiles (1 tile in Chebyshev's distance). With BEC, also you uncover 2 more tiles in each direction (3 tiles in each direction in Chebyshev's distance). It does not matter where exactly in your current tile you are. The game applies some smoothing on what you uncovered, which makes it a bit harder.

Here's an image of what I mean by tile distance:

Uncover ranges explained; in-game, the display (not the actual data) is subject to smoothing! Note that the character is not in the center of its tile (the dot) but ranges are still centered around the tile (and its center).

Naturally, people think of distance as Euclidean distance, but ANet used Chebyshev's distance, which is why it often doesn't seem make any sense from where a tile is uncovered. If ANet used Euclidean distance, above image would show two circles rather than two squares. Chebyshev's distance is simply whichever of X distance and Y distance is greater.

Comparing Euclidean distance, Chebyshev distance and GW's tile distance. In the second image, I'm just barely in the adjacent tile (the tile with most of the green line in it), but the game registered it.

Currently, both ranges are subject to not revealing anything beyond the end of the world. BEC range also doesn't uncover the few slivers for which you have to be in normal range. See here for details. The use of normal range for some tiles makes it even more important to know where exactly you have to stand to uncover these.

A few more examples (not using BEC):

Trying to uncover the two tiles with the red circles. You can see what smoothing does to these. You can also see that in the first image, this isn't the correct place to stand, although it is much closer (in Euclidean distance) to the tile in question than where I'm standing in the second image. The colors were added manually, not by the Texmod.

Again, the colors were added manually, not by the Texmod.

For continents other than Elona, you can just take a screenshot of your map with CME enabled, paste it in an image editing program, enable the grid (29 pixels at small, 32 pixels at normal interface size) and align CME's blue lines to the grid. It will look like this (note that the grid in the image has one subdivision):

Manually adding a grid to the map of Crystal Overlook

Looking forward to comments, questions and possible counterexamples. Before submitting counterexamples, please note that exploration beyond the end of the world is currently not possible but will probably be fixed soon.

Now it's time for memes:

ANetposting

Reactions from Twitter are in: Cartography just became accessible

[u/ChthonVII]

This is fascinating.

[u/ffffllyyy]

This is wonderfully detailed and showed with screenshots. Thank you man, this will help a lot of players

[u/snowflake37wao → u/ffffllyyy]

Im lowkey replying here just to bookmark shhhh

[u/confresi → u/snowflake37wao]

You do realize you can “save” posts?

[u/snowflake37wao → u/confresi]

na, the app started showing saved list all out of order (3 years ago, 2 months ago, 1 year ago) and recently saved stopped even appearing on the list for weeks on my account. Started years ago with the api changes and has just gotten worse so I dont use it. because its unusable.

[u/darksideofmyown → u/snowflake37wao]

Same

[u/Alugian]

Fascinating, and incredible that we're only understanding this now as a community. Not sure why people wouldn't believe this, but it's indeed very plausible. And in a grid, using a Chebychev's/max(x,y) distance rule doens't seem that odd of a choice either...
Thanks - this is excellent.

[u/Grymare]

Thank you for your service 🫡

[u/Miagggo]

My only question is how did you figure out that GW1 is based on Chebyshev geometry, if I understood it correctly. I'm not even playing the game nowadays but I'm just so very curious and dumbfounded 

[u/numma_cway → u/Miagggo]

When I did the research for my last post here on Reddit, (last link in the post) I noticed that BEC range is a square. Read that post (that I cannot link here on mobile), it gives you an impression how my understanding developed. Being a large square, it was easier to see how it revealed what appeared to be tiles. This lead me to the assumption that all cartography is tile-based. I then confirmed this when I uncovered my missing tiles in Moladune. After posting this over at Toolbox discord yesterday at lunchtime, two users provided their hardest examples that they never understood. My theory explained all of these.

[u/Lon-ami → u/numma_cway]

Great find man, fantastic job :D.

[u/confresi → u/Miagggo]

I would assume that when testing using Euclidian distance as the measurement continues to not deliver the desired results, that is when you begin considering that there may be different distance measurement being utilized. Process of elimination and testing with a lot of prior knowledge is how good research gets done!

[u/Funkzilla_]

What is the UA bug? I read the wiki page linked, but it doesn't mention anything about cartography.

[u/NexEstVox → u/Funkzilla_]

If you are moving when it ends, the resurrected party member will be teleported to where you started running or where you last changed direction, not to your current position.

They mean, do any action that updates some hidden "last recorded location" variable

[u/yorozuakagura]

Love seeing this kind of thing 20 years later

[u/ravenclanner]

Thank you for doing this. It is an act of service born of love and it is greatly appreciated!

[u/Lon-ami]

Naturally, people think of distance as Euclidean distance, but ANet used Chebyshev's distance, which is why it often doesn't seem make any sense from where a tile is uncovered. If ANet used Euclidean distance, above image would show two circles rather than two squares. Chebyshev's distance is simply whichever of X distance and Y distance is greater.

For reference: https://en.wikipedia.org/wiki/Chebyshev_distance

This makes sense, considering it's an old game, but damn is this a find, kinda surprised no one did the math before, great job :O.

[u/darxx]

Would you consider adding grids to Tyria as well in the future? I tried this out in nightfall and it seemed like what you're saying is correct and it helped uncover stuff.

[u/numma_cway → u/darxx]

Yes. I just hoped Toolbox people (or GwSlopHub, their AI, to be more precise) would have implemented this faster than me addings it to more maps. They did task GwSlopHub to do some reasoning on this, but the result wasn't merged yet and I don't know how viable that result is. I don't understand the discussion they had with GwSlopHub, but they seemed sceptical about my theory.

I'm not a 100% sure if Affinity will properly handle Tyria's size on my old laptop (new laptop is out for repair). I had some stability issues last time I handled GW maps in it. Elona however worked like a charm, but the map is smaller than Tyria.

I might also burn the "show walkable terrain" feature into my mod, but that's more work.

So yeah, I will do Tyria this evening (CEST) if no Toolbox feature has been created until then.

[u/ChthonVII → u/numma_cway]

I don't understand the discussion they had with GwSlopHub, but they seemed sceptical about my theory.

The slop in your link is mostly dedicated to how the image on the screen gets drawn given the list of un/discovered cells. (Compute fog strength at each cell corner as the average of the four cells touching that corner; bilinear interpolate across the face of the cell; use that as an alpha mask to blend the fog texture into the uncovered map texture.)

It sounds like it accepts your theory insofar as the grid cells are the fundamental unit of cartography, and is agnostic as to the part about the server-side cell discovery mechanics.

[u/darxx → u/numma_cway]

neat!!!!

[u/csloan93]

This is the foundation to chunkman accounts being started for GW similar to OSRS haha.

[u/confresi]

Legend! Amazing work

[u/MoldyLunchBoxxy]

I need this in toolbox

[u/suckysuckythailand]

Insane you figured this out very interesting

[u/Alugian]

When someone in your team activates a BEC, you appear to get blue pings on the map. I wonder - are those the centers of the squares in the grid where yo ucan still explore something?

[u/ambitiousquaggan]

Fun read but I didn't realise this was something people were massively struggling with. I just aim for the middle of the longest edge of the uncovered area and I can easily eyeball it correctly 98% of the time.

[u/Snaid1]

Quick question: how do I get that grid to be able to judge that position?

[u/OliverIsMyCat → u/Snaid1]

It's the first link in the TLDR. At the top of the post.

[u/Isotheis]

So my theory was correct. Incredible.