Theory

Zoom Levels

When discussing resolution of the source image to tile with, it’s best to do it in the context of “Zoom Levels”, something in web cartography that refers to pixel-per-meter-resolutions of terrain. In OCAP2, we use a CRS (coordinate reference system) that’s fairly arbitrary. Unlike real-world data, we’re starting already zoomed very far in to the terrain data we take out of the game world. We’re also viewing data taken from a flat game world, rather than a curved spheroid. Our web mapping framework (Leaflet) supports mapping onto such a flat plane — some of the backend may change moving forward so distances are properly represented by the map scale during playback, but for now, native tools like a map scale reference will not show accurate values.

Zoom levels 1-17 in the context of real-world data. Credit

You can read here for more on Zoom Levels:

Understanding Map Tile Grids and Zoom Levels

Tile Resolution

Any kind of web mapping system needs a tile set that can be quickly loaded on client machines. While the nature of tiling itself optimizes the resolution of what a person sees based on how far zoomed in they are, the backend storage of these tile sets grows exponentially for each additional zoom level that’s accounted for.

A majority of OCAP2 maps are rendered up to Zoom Level 6, using a 16384x16384 pixel source image. World sizes smaller than that (exported at 1 pixel per meter) are often upscaled.

In some cases, large worlds like Altis (30270x30270) are kept in original resolution so that tiles can be generated up to Zoom Level 7, providing better playback resolution to see individual buildings, roads, and terrain features.

Limited Color Mapping

In addition to compression methods using ECT, images rendered off of the original topographical map export are limited to 255 colors. This minimizes the disk space required to store color data for tiles, achieving greater compression.

Gather Terrain Data

Run Arma 3 as Administrator
1. You can run Arma3Launcher.exe from your Arma install root as administrator to then select and run any addons.
<aside> 💡 You will need to run at least CBA and the addon containing the terrain to render.

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Select 3DEN Editor from the main menu, then choose the terrain
Press Ctrl-O while the terrain is selected, to open the 2D Editor