`timestamp` doesn't consider pause time

[rhalaly]

Bug report

• AirSim Version/#commit: 8057725
• UE/Unity version: 4.27
• autopilot version:
• OS Version: Windows 11

What's the issue you encountered?

It seems that #4305 didn't fully solve the issue (@zimmy87 can you assist please?). Trying this piece of code:

import airsim

import time

client = airsim.CarClient()
client.confirmConnection()
client.enableApiControl(True)

prev = client.getCarState().timestamp

client.simPause(True)  # Pause the simulation
while True:
    curr = client.getCarState().timestamp
    delta = curr - prev
    prev = curr
    print(delta * 1e-9)

    time.sleep(2.0)  # Sleep for 2 seconds - should be ignored by the simulator
    client.simContinueForTime(1.0)  # Continue the simulation for 1 second
    while not client.simIsPause():
        time.sleep(0.1)

This code sleeps 2 seconds while the simulation is paused and continues the simulation for 1 second. So the expected output should be 1 second since the simulation was played for 1 second every time.

But got the output

Connected!
Client Ver:1 (Min Req: 1), Server Ver:1 (Min Req: 1)

0.0
5.6500268
3.0188154000000003
3.0312138
3.0336949
3.0241089000000003
3.0263058000000003
3.0252388000000003
3.0206698000000003
3.0262011
3.020782
3.0155367
3.0184487
...

If I ignore the first value, I don't fully understand why I get 5.65 (and other high numbers) in the first reading. But after that, I get 3 seconds constantly instead of 1 second as expected.

Settings

{
  "SeeDocsAt": "https://github.com/Microsoft/AirSim/blob/master/docs/settings.md",
  "SettingsVersion": 1.2,
  "SimMode": "Car"
}

How can the issue be reproduced?

1. Build AirSim with commit 8057725
2. Run the above code

Include full error message in text form

No error, just unexpected result

[zimmy87]

I've put out #4385 which should fix this. Please retest with my fix applied and let me know if you notice any issue. Also, during testing, I observed that the scaling of timestamps changes between "ScalableClock" and "SteppableClock" clock types. Specifically, "ScalableClock" will result in timestamps that are scaled by a factor of 3, and "SteppableClock" results in timestamps that appear to correspond directly to wall time, regardless of whether you are in car or multirotor mode. Please note car mode defaults to a "ScalableClock" and multitotor mode defaults to "SteppableClock", so you will have to explicitly set the clock type in your settings to test for feature parity between car and multirotor modes.