Factorio replay timelapse recorder

Make timelapses from your replay saves!

This script can be attached to an existing replay save file to generate a timelapse by running the replay. This does not register as installing a mod, and so does not invalidate the replay.

Importantly this also means you can do this with existing saves, and you can re-run the recorder any number of times while tweaking the settings to your liking, so you don't need to know up front what frame rate, resolution, zoom limits, etc., you want. And of course, it doesn't count as a mod for the purposes of achievements or the like.

The only editing added to the above gif is the fades between cuts.

Full length example, lightly edited: https://www.youtube.com/watch?v=r0UNzrjfYkE

Usage

To use this tool:

1. Unpack your save file into a new directory. The save file already includes a prefix directory, so for example MyBeautifulBase.zip will by default unpack into a new MyBeautifulBase/ directory.

2. Take the control.lua file from this directory and append its contents to the control.lua file in the extracted save directory, for example MyBeautifulBase/control.lua.

3. Copy the replay-timelapse.lua file into the extracted save directory. For example, copy it to MyBeautifulBase/replay-timelapse.lua.

4. (Optional) At the top of MyBeautifulBase/replay-timelapse.lua, tweak the output paths and/or program parameters as needed. See the comments in the file for descriptions.

   The default settings generate screenshots at 1080p, 30 FPS and x300 speedup (5 in-game minutes per second of timelapse), saving them into script-output/replay-timelapse/ in the Factorio application directory.

5. Launch the game, load the extracted directory - for example, MyBeautifulBase/ - as a save file, and run the replay to completion. You may play it at any speed.

On Unix-like systems, the script install.sh can be used to perform the first three steps.

NOTE: Make sure to prepare plenty of disk space for the screenshots. With the default settings (1080p @ 30 FPS, x300 speed), screenshots consume about 9 GiB per timelapse minute or about 2 GiB per in-game hour.

Once finished, you can use FFmpeg with the image2 demuxer to assemble the screenshots into a video file. See the assemble-timelapse-videos.sh script for an example.

Camera movement strategy

Initially, the camera movement strategy is rather simple: keep all buildings on screen and zoom out as necessary. The camera keeps track of the largest bounding box the base has occupied so far, and pans and zooms out to keep that whole bounding box on screen. If the base shrinks to be significantly smaller than the bounding box, then after a short delay the relevant dimension of the bounding box is reset and the camera smoothly zooms back in to make the best use of screen space.

However, the camera cannot zoom out forever. Things get too small to see, and the game doesn't allow zooming out too far either. So when the whole base no longer fits on screen, the movement strategy changes. Now the camera will instead try to cover everything built by the player (but not by robots) in the last 2 timelapse seconds - both actual entities and entity ghosts. This seems to strike a reasonable balance between keeping things big enough to see, not moving the camera too much, and covering the most relevant area at any given time.

Research timelapse

The timelapse recorder also writes research progress to research-progress.csv and research-finish.csv. The research-timelapse/ subdirectory contains tools for using these files to generate a research status window for the timelapse.

Credits

This was heavily inspired by this gist by Bilka and the mod Time Lapse Base Edition.

License

GNU General Public License, version 3 or later.