The issue was reproduced in a vanilla Arma 3 setup, with no community mods enabled and no additional cDLC content loaded.
Infantry equipment changes its thermal appearance abruptly when crossing a very specific distance threshold around the displayed range of approximately 1175 metres.
I reproduced this in a simple Eden Editor scenario at Stratis Air Base. The observing player is positioned near the southern end of the runway, and six AI units are positioned near the northern end.
The AI are arranged in comparison pairs, including comparable units with and without the vanilla Stealth Balaclava facewear.
When moving only a very small distance towards or away from the AI at approximately 1175 m, the thermal rendering of parts of the soldiers changes immediately instead of remaining visually consistent.
This is especially noticeable with the Stealth Balaclava. Its thermal masking of the face is not rendered consistently at this distance. Crossing the distance threshold can cause a significant change in how much of the hot face is visible.
The attached “step closer” and “step further” screenshots demonstrate two different rendering states. In both states, the Laser Designator range display may still show 1175 m, presumably because the displayed range is rounded.
Importantly, even in the “step closer” state, the Stealth Balaclava is not rendered consistently on every AI unit. Some units retain the expected cold/low-signature face covering, while others show a partially or clearly exposed hot face.
Therefore, the issue does not appear to be a simple case of one side of the distance threshold being correct and the other incorrect. Instead, crossing the boundary changes which parts of the infantry equipment/facewear are thermally rendered or visible.
The issue is visible through the vanilla Laser Designator (Khaki) thermal optic at both approximately 5× and 25× zoom.
I also included an additional screenshot taken through ENVG-II thermal vision, zoomed using the "+" key, as another reference for the thermal appearance.
The scene, AI units, equipment, and graphics settings remain unchanged. The visible thermal rendering state changes simply by moving a very small distance across this approximate range boundary.
I also repeated the test after increasing the video quality settings to Ultra. This did not resolve the issue or noticeably change the approximate 1175 m transition point. The same abrupt thermal rendering change remained visible.
Steps to reproduce
Open Stratis in Eden Editor.
Place the player near the southern end of the main airfield runway.
Place several AI infantry units near the northern end, approximately 1175 m from the observer.
Use comparison units with and without vanilla Stealth Balaclava facewear.
Equip the player with the vanilla Laser Designator (Khaki).
Switch the optic to thermal imaging.
Observe the AI at approximately 5× zoom.
Move a very small step closer to the AI and observe their thermal appearance.
Move a very small step farther away again.
Repeat around the ~1175 m boundary.
Repeat with the maximum approximately 25× zoom.
Compare which parts of the facewear/clothing remain thermally visible in each position.
Result
Crossing the approximate 1175 m distance boundary causes an abrupt change in the thermal rendering of infantry clothing and facewear.
The thermal concealment provided by the Stealth Balaclava can also change, making the hot face significantly more visible.
Even on the closer side of the transition, the Stealth Balaclava is not rendered consistently on every AI unit.
Expected result
The thermal appearance of infantry clothing and facewear should remain visually consistent when the observation distance changes by only a very small amount.
A distance-based rendering transition should not cause a major change in the thermal signature of the equipment or suddenly expose a hot face that was thermally obscured in the previous rendering state.
If a model/LOD transition is involved, the relevant thermal material and face-covering geometry should remain consistent between rendering states.
Actual Result
At around the displayed range of 1175 m, there is an abrupt transition between different thermal rendering states.
Even on the closer side of the transition, the Stealth Balaclava is not rendered consistently on every AI unit. Some subjects retain the expected cold/low-signature face covering, while others show a partially or clearly exposed hot face.
Moving only a very small step closer or farther can change which subjects or equipment parts are affected.
Increasing the video quality settings to Ultra does not resolve the issue.