What happened?
When testing a yumako tree farm, I noticed thin blue lines appearing above certain trees during growth. These only appeared for a frame usually, and don't seem to occur for fully-grown trees.
- Yumako tree blue line gfx bug
- factorio_2024-11-22_16-18-30.png (1.57 MiB) Viewed 689 times
Make sure to zoom in, as the lines are 1 pixel thin
Attached is also my save file (with some other unrelated stuff), as well as my factorio-current log file after closing the game. I use Editor Extensions for some editor enhancements, but I think this should work in vanilla too.
I use an RTX 3070 on a 1920x1080 display, and play in borderless window mode at full screen resolution, with high sprite resolution, high quality texture compression, and largest possible atlas size.
More details
When the blue lines show up, they're visible only at certain zoom levels. The screenshot shows the trees at maximum zoom level. Oddly enough, this is only consistent for a surface, but not for different surfaces, even with an identical cloned entity. For example, the save file has a surface called "test", where the blue line shows up at the nearest zoom level. These same trees (area-cloned multiple times) come from the nauvis surface, where the blue line shows up at both the nearest level, as well as when zooming out 6 scroll wheel steps. Notably, cloning the entity itself (with freeform placement) tends to not produce the blue line reliably (though I've managed to trigger the blue line bug on a held ghost of the tree once), but area clones (with the same grid-relative alignment produces the blue lines reliably (though, as noted, not so reliably between surfaces for some reason). It's also worth noting that the line appears behind the tree sprite, and removing the sprite removes the blue line too.
To reproduce:
This issue can be reproduced by planting a bunch of trees, waiting for them to grow a bit, and then frame-stepping until a blue line shows up. This bug happened to me at around 70% tree growth, but it's possible that it can happen anytime. I suspect this may be dependent on graphics hardware or other subtleties, so YMMV.
On an unrelated note, I thought I was being smart by wanting to plant quality seeds to get infinite quality fruit, but it doesn't seem to be as simple as that. Oh well, back to regular quality processing I go.