I have a theory which may explain the link between the missing replay data and strange physics feeling. And it relates to a post by SuperSic earlier in this thread. Initially I disagreed, but now I think I understand the point SuperSic was trying to make.
It's like those affected by the bug are suffering 'micro-pauses' within their game world. I'll try to explain.
Missing replay data
Earlier in this thread I posted some replay timing data from a bugged replay;
Free-run lap : 2:11.8 (game clock)
2nd flying race lap : 2:17.6 (game clock) - 2:11.6 (replay data)
Around 6 seconds lost.
There seems to be a strong correlation between the amount of lap time lost and the amount of missing replay data based on this example (and other bugged replays I myself and other posters have tested). The time difference in this example is around 4.5%
Working on the assumption that GT5 is running at 60fps (I know it's not solid 60fps but the actual framerate is not really relevant) then the 'stuttering' could be from the game pausing frames 2 or 3 times per second. Tiny pauses of this nature will be detectable to the naked eye - and will be worse if the time difference is something in the realm of 15 seconds like some have been reporting.
The game timer clock continues to run during these 'pauses' but the paused frames are not recorded by the replay data. This would account for the time difference between the game clock in a bugged replay and stopwatch time.
So while your bugged car is pausing 2 or 3 times per second (each pause less than two hundreds of a second) the unaffected car next to you has moved on up the road just a little.
Physics change
I described the change as a loss of grip, power and braking. But now I think I see what SuperSic was getting at regarding our perceptions of speed and grip.
I noted before that the time lost for this example lap was 6 seconds (approximately 4.5%)
Now consider your car is travelling at 100km/h - but the game is 'micro-pausing' 2 or 3 times per second. Because of these added paused frames the driver perceives or 'feels' the car to be travelling slower than it actually is in the physics engine. Because the driver perceives the vehicle to be moving 4.5% slower (say 95.5km/h) than it actually is then they will brake at an appropriate point - based on their perceived (slower) vehicle speed.
However, the car is not travelling at 95.5km/h in the game engine. It's actually travelling at 100km/h and the braking point selected by the driver is too late! Not only that, but now that they've hit the brakes (and the game is still micro-pausing) the car is now taking 4.5% longer (in perceived time by the driver) to pull up for the corner.
Cornering has the same 'slow' feeling. Due to the micro-pauses the car is perceived by the driver to be travelling slower than it should! And relative to the rest of the unaffected cars racing - it IS travelling slower!
This theory would explain:
- The slow lap times
- The framerate stuttering
- The lost replay data
- The perceived loss of grip and power.
