A very long race can be done in S2.
However, because it is not possible to rewind it when the replay of the race
is seen, it is very inconvenient.
It is needful function.
other racesims can it.

Been suggested before, and right now it is not possible to code anything for rewinding the replays. Something about the replay being read as a "story" I guess you could say, and you can never rewind it... goes only in one direction.

This is why replays are such small files in LFS. If we had rewind and all those other VCR features other games have, we would have HUGE replays just like they do .

The laws of physics only work in one direction. i.e. if you know where a car is resting, the game can't apply a randomly generated acceleration force to bounce it off a wall, into another car, and onto the racing line.

The only solution, as far as I know, was suggested by Scawen a few months back, and that was to make 'key frames' within the replay that you can hop to as and when. How long that would take to program, and when he is likely to start programming it I don't know.

Another solution that I've just thought of (though I have a large cold at the moment, and the snot can't be helping the thought processes) is to have a time bar at the bottom. Say you know something interesting happens at 10m35 into the replay, but you missed it. So you click GoTo (and type 10m30), and the replay stops. Meanwhile, in the background, LFS nips through the replay at 100x or something, without graphics. When it's ready, it pops up (paused) ready for you to set camera angles etc.

Of course this will only work if turning off the graphics allows LFS to run much much faster, as my PC struggles with 32x, so 100x would kill it.

Just a thought...

Haha, yeah. At 32x my comp goes into 1FPS mode

Seriously, I think the combination of key frames and that quick-spool tristan mentioned are the way to go here. You should only see the position bar and be able to move it around, but internally it doesn't always calculate everything from the beginning but uses the nearest key frame to speed things up. This would be optimal IMO.

But.... only Scawen could say if that is possible I am pretty sure he knows there should be rewind in replays, it is just how it will be done that is the trick. On RSC he discussed it once I think and noted that it may involve changing how replays are recorded or something... as well as mentioning it would be very time consuming to figure it out. That's all I remember.

Well, we just said how it would work: with key frames. They would be a "snapshot" of the current world state with every variable saved. Actually "rewinding" isn't possible, but jumping back to these key frames and playing back from there surely is. I don't even have to know how Scawen's code looks to be sure that this would work.

And then you could set how often the keyframes are.

Quote from AndroidXP :

Well, we just said how it would work: with key frames. They would be a "snapshot" of the current world state with every variable saved. Actually "rewinding" isn't possible, but jumping back to these key frames and playing back from there surely is. I don't even have to know how Scawen's code looks to be sure that this would work.

Even if the program only thought about the info between each keyframe as separate files, then opened them as it got to each keyframe.

hi,

maybe such a keyframe could be saved at every lap/ or every sector?!
Don't know. But it would be very helpful to jump through the replay lap-wise.

I mean like in "Nascar Series 2003" where you can click on a button and then the replay jumps a lap forward (or backward).

Wasnt there a program that u can put ur replays into and u can rewind/fast forward?

Quote from tristancliffe :

(though I have a large cold at the moment, and the snot can't be helping the thought processes)

Thanks for sharing!

If this would make the mpr/spr too big, then maybe there could be an option in LFS - Create Key Frames, that took an mpr/spr file and made key frames in it, say every time the driver/leader exits the last corner. A new file is created with the ending .wkf.mpr or .wkf.spr.

What I think would be useful is a system like this:

When you fast forward at more than 2x speed, LFS ignores the physics and only updates the car positions. That would increase the fast-forward frame rates and mean that you could skip or rewind at will.
Then when you go back to 2x or slower, it applies the physics to the objects as they should be. Since physics behaves the same every time, that shouldn't cause any OOS problems, but it would potentially mean that a record would need to be kept of the physics acting on the car every frame rather than replying on specific events to play out, which might be a problem.

Either that, or give you the option of saving either a full replay that you can't skip through, or a purely positional one that you can.

LFS doesn't need to store the key frames in the replay -- it just needs to cache them as it reads the replay. So if you view a replay, arrive at lap 8 and decide you want to go back to lap 5. LFS will have kept a copy of the full state at the start of that lap, in memory or in a temporary file. Going back to lap 5 can be done instantly. No need to change the file format.

This brings you back-skipping. For forward-skipping, LFS could use the technique described in post #3. True rewinding (= reversing the direction of time) is much tougher, because the physics can only be calculated forward. You'd need to cache more frames -- 1 per second or so -- to get a smooth backward motion. Or you'd have to drop the physics-recalculating stuff and adopt a purely frame-based replay format.

If LFS does not discard the key frames but stores them in a permanent file, then it can re-use them next time you view the replay, so skipping forward will be faster.

Keyframes are the answer.

So? Anybody knows if it will be implemented? Rewinding last 5th lap is very boring...

You can rewind and fast-forward replays...

You can't "seek" but being a replay based off the physics/actions you won't be able to seek (without getting faster computers).

It seems Tristan's cold didn't hamper his ability to predict the future

Rewinding is different issue. Maybe skipping is the best solution. I'm just thinking about the DVD chapter system. Shortly, chapters in DVD would be laps in LFS. Of course, if possible...