AI detection at night with moonlight and lights

[FlintMcgee]

 

I've been looking into how AI units detect aircraft at night, and the results are actually really interesting. After checking through the detection.lua file and running a bunch of tests, I found that sky_bodies_illumination_factor is set to true, which means the moon phase directly affects how visible you are to AI. The game uses four moon stages quarter, half, three quarter, and full, with each one adding more light that helps AI spot you more easily against the night sky.

sky_bodies_illumination_factor = true,
other_light_sources_illumination_factor = true, --no effect if sun_illumination factor disabled
darkness_threshold = 0.0, --no effect if sun_illumination factor disabled

What stood out the most in testing was how external lights change your visibility. The parameter light_source_detection_distance is set to 10,000 meters when light power is at full, and my tests showed that position lights make you a lot easier to see and far more likely to be engaged by AI. Strobe lights also increased detection, but not as quickly as the position lights, while formation lights barely made a difference.
 

as_light_source = {
    light_source_detection_distance = 10000.0 --for light power = 1.0f
},

The file also shows that other_light_sources_illumination_factor is set to true, which means your own aircraft lights actually light up your airframe and make you glow against the dark background. In other words, you are basically making yourself a visible target when your lights are on.

Another important part is the darkness_threshold value, which is set to 0.0. That suggests AI detection does not completely disappear at night. It is just greatly reduced unless you are illuminated by your own lights or the moon.
 

max_detection_distance = 50000.0, --m, absolute limit

But detection times increase significantly at longer ranges
 

average_det_time_max_dist_0 = 1.0, --s, average detection time of target ahead at the maximal distance
average_det_time_max_dist_180 = 10.0, --s, average detection time of target behind at the maximal distance

Overall, both the code and testing show that flying with lights on at night, especially under a bright moon, makes you far easier to detect and engage. What should be the cover of darkness actually turns into a disadvantage if you are not careful with your lighting.

 

Contributer: @mach_point_yuh, @lightningw0lf, @zenki1419

Edited Wednesday at 10:40 PM by FlintMcgee
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