As we all know there will come a patch that includes changes in the physics engine.

I've read some time ago in this forum that in the replay-files the physics-data is stored and thats also the reason why you cannot rewind when watching a replay.

Will the replays of today still work with the new patch?

i think its safe to say no.

Yah every new patch which fixes or changes a lot of things will ultimately make most old content unusable.... especially replays.

Definitely no.

The replays don't contain any "physics-data" but only the user inputs for SPR files or the position/user-input packets for MPR files. While viewing the replay, these inputs are fed into the physics engine, thus relying on the physics engine to give the same results as it did when the race was being recorded.

Now, if you change the tiniest detail on the underlying physics engine the whole system doesn't work anymore - the replay goes OOS (out of sync), because the same user input is suddenly producing different results.

exactly, this is why i have 5 different LFS directories from one of the earliest demo

6 here :P

Only 1 here...
Well that would be why all hotlaps will be lost at the release of the new patch

I wonder what else may be affected. I'm thinking about LFS World data generally - pbs, mileage and race results etc. I suppose there's no real reason to lose some of this but I guess PBs will be pretty meaningless following physics changes.

I dunno about PB's but hotlaps will definitely be deleted after the patch.

Quote from Gentlefoot :

I wonder what else may be affected. I'm thinking about LFS World data generally - pbs, mileage and race results etc. I suppose there's no real reason to lose some of this but I guess PBs will be pretty meaningless following physics changes.

My old MRT5 pbs from S1 still exists.

Cool - cos I reckon a lot of my PBs are gonna be smashed if there's a load more low speed grip.

In one way it is a bit sad though. I have many gigabytes of mpr files and I guess they are incompatible with the new version.

[insert a humble request of replay viewer here]



Yes, I am complaining about the new patch now

pb's stay, but I always delete the ones that aren't acheivable with new physics. If a certain car on a certain track is 1sec slower then bye-bye pb. If it's quicker with the new physics then I leave them knowing that it'll be overwritten soon enough

or your could always install 2 version of lfs and keep the old one just for replays...

Quote from AndroidXP :

Definitely no.

The replays don't contain any "physics-data" but only the user inputs for SPR files or the position/user-input packets for MPR files.......

That's not true (at least for SPRs) and you know it.......think about how it would be possible to "Test drive" the SPR with only the parameters you said...without any physics data

Can anyone actually say they KNOW the answer for sure?

My guess is the physics engine is not encapsulated within the replays themselves, instead being more like a run-time environment within which the SPR/MPR data operates.

I think the mpr/spr files just include the inputs for the car (wind, steering, accelerator, other buttons etc.) and LFS checks these inputs and "drives" the car accordingly. I remember once seeing a corrupted spr file where the car spins into a wall but keeps accelerating and braking like it would still "be on the track". I drove that spr myself and I didn't spin But it was in the S1 days...

Quote from Razzone :

That's not true (at least for SPRs) and you know it.......think about how it would be possible to "Test drive" the SPR with only the parameters you said...without any physics data

You can test drive a car from an spr because the replay also contains the setup, this has nothing to do with the physics engine.

Old replays will DEFINATELY not run on a new physics engine. Same reason why the hotlaps are going invalid (they're nothing more than replays, remember?).

The physics engine is in LFS. Replays only contain input data/multiplayer packets, it would be plain silly if they contained the physics engine. Sending them through the wrong engine will simply generate wrong results.

As has been suggested, if you want to keep viewing your old replays, copy your old LFS directory somewhere before upgrading.

I hope there will be rewind possibility in new patch. It can be done thru "keyframes" every 30sec or so. If not, we'll wait next year or longer for next physics update => next possibility to change spr/mpr format for rewind support
It's annoying to judge accident in long races now..

id quite like to see the replay controls they used in ea f1 99-02. Hva ethe replay timeline load up and just scroll along it back and forth to view the replay....

Quote from Madman_CZ :

id quite like to see the replay controls they used in ea f1 99-02. Hva ethe replay timeline load up and just scroll along it back and forth to view the replay....

Stepless rewind isnt possible because of way how replay data is interpreted. But 30s steps are relatively "easy" to do.

Quote from Pablo.CZ :

Stepless rewind isnt possible because of way how replay data is interpreted. But 30s steps are relatively "easy" to do.

What if LFS could record a ISI/Papyrus-like replay from the SPR and MPR files, storing it temporarily on your harddisk.
Then the replay files will still be small enough for lfsworld and we can rewind them. We wouldn't have to wait a year for the next physics patch either.
It seems logical or am I missing something?

Quote from bobvanvliet :

You can test drive a car from an spr because the replay also contains the setup, this has nothing to do with the physics engine.

Infact I was discussing about PHYSICAL DATA and the "Definitely no.." referred to physical data contained in SPRs. So said it's perfectly clear that old replays won't be of any use with next patch.

Just like old replays aren't of much use anymore either. And why ORION has 6 LFS installs (other than having nothing better to do).

I've currently 8 LFS installs on my computer plus the skin viewer, although I'm currently only using two of them.