Close vehicle proximity causes lag in time warp

[Kiwi Shark]

Game Version​

2026.7.10.5056

Operating System​

Windows 11

What Happened​

While time warping (~x86400) while controlling a vehicle landed on the Lunar surface, the game suddenly hit a huge lag wall and ground to a halt. Repeated loads of the save and warping again showed the issue hitting at the same point in time at different speeds. Deleting all other vehicles and warping removed the lag wall. The issue was found to be Hunter and Gemini7 happening to drift close enough to each other at that point in time to where their action bubbles intersected. At less than ~10m proximity, noticeable lag is induced at increasing warp speeds (600 or 1200x at least).

From @tomservo who was helping diagnose at the time:

Reading Opus' analysis and it sounds plausible that there's a real gap in the logic here, the time warp plays into how big of a radii needs to be accounted for when guessing if a collision detction needs to occur during that time step, and there's a performance cliff due to some [probably] missing fast path optimizations for certain scenarios like this one

What Was Expected​

I expected not to be hit with such a slowdown, especially from vehicles not under active control or in proximity to my followed vehicle.

Reproduction Steps​

1. Load attached save file "lag warp bug testing".
2. Set time warp to x86400 and wait until Hunter and Gemini7 drift within 10m of each other.
3. Lag should incur. Setting warp back to 1x should return framerate.
4. Warping again will bring lag back.

Reproduction Rate​

Always.

Additional Info​

Example on VOD here. Timestamp 2:14:37 or so.