Quote from garph :

You hit something and your car breaks.

:uglyhamme
Good point! Maybe in a not too easy to understand way but more technical?

Thanks Scawen for not being offended for the massive invasion

Quote from garph :

Everyone has experienced this bug and it has pissed everyone off at some point but no other league seems to have had problems with it on the same scale as this league seems to be having with it.

Again, not trying to argue just pointing that out.

You got a point there garph, but once again the reason is that we're hosting races for lots of newbies who makes a lot of mistakes and they are the really damnified of the consecuences of this bug. This does not happen in 1st and 2nd divisions where accidents aren't that common and most of the drivers end the race

The patch X includes +12 drivers in each race so there are more probabilities to have accidents than before this patch

Btw I'm not really worried about the bug hitting a fence (South City being the exception :P) but about collisions between cars wich are very common in every race and sometimes have very unrealistic consequences


Thanks again to Scawen for taking time to read our thoughts and explain how the wip is going (even though he doesn't need to do it)
I hope you already have something in mind to avoid this bug and make the game more realistic
Hell I can't wait to see the next change in physics even if that means throwing all my hotlaps out of the window

Quote from Scawen :

In short, don't worry, in the next bunch of physics changes I will be looking at improvements to the collision system.

that's all I think we needed to read


btw, we wrote this thread becouse we thought next patches would be physical patches, as you said at some thread. We're not questioning your way to work

Quote from Scawen :

In short, don't worry, in the next bunch of physics changes I will be looking at improvements to the collision system.

That's all I needed to read, I didn't know if get this bug fixed, was on your list of physics updates,


Edit: Dexterbdn, you read my mind xDDDD

Quote from Scawen :

Well this thread gave me a laugh... in a nice way

I bet his laughing at some of my buddies because of their english speaking skills :P

I couldn't understand anything myself in a couple of posts lol

Quote from Vykos69 :

Again, the tracks are not an excuse. If you drive e.g. Fern Bay with the small GTRs, it is well known, that you can easily flip on the curbs.

I've seen TBO's race there with only 2-3 not finish, because while the drivers were quick we all know that the car stays airbourne over the kerbs we need to be REALLY careful - in LFS clipping those Kerbs might roll you but IRL hitting them tyres would smash your radiator/bumper

+1 i agree

Thanks Scawen !!!

Nobody is talking about your way is incorrect, Spanish comunity ( ok... some members ) want you to take a look about collisions.

Thanks for your post.

Refered to members of lfsworld community, please, you are invited to drive at our servers and you could look that much of words we post here today were out of place ( excuse my english, is poor than my driving skill )

A small part of people who are driving in lfs-spain community take the start only thinking about won at all costs .

Thanks to all for today words!!!

Quote :

By the way... to make this a bit clearer... Can anyone explain how the collision system works in an easy to understand way?
Thanks in advance!

I'll do my best from what I understand.

LFS has two physics engines: Complex & Simple. The complex engine is used for the drivers car, the nearest car behind, and the nearest 3 cars in front.

The complex engine features all of LFS' goodly physics stuff but is heavy on the processor.

The simple engine uses a lot less calculations and recreates similar results but does away with some of the fine detail, such as car roll, which you dont notice on cars in the distance.

The transition from simple to complex physics can cause cars having accidents at turn 1 to 'jitter'.

For the purposes of this post i'll talk about the complex system, as that's basically the physics engine of LFS. The simple system is just a shortcut for making the game work on our lowly PC's.

The physics engine updates at 200 times per second, irrespective of other factors, during each update of the physics engine cars move a certain amount based upon their speed etc etc. Now, imagine a car is moving at 100mph, so it moves 100 'units of 3d space'.

Now imagine that there is a barrier directly infront of it, 1 'unit of 3d space' away. When we strike the barrier we hit it and overlap by 99 'units'. However, if the barrier was 99 units away we would strike it and overlap by 1 'unit'. So two identical impacts at 100mph result in two very different results.

The solution is to change the way accidents are calculated and use factors such as combined speed mass, attitude, impact absorbtion and so on. Doing this is more complicated than the fast and cruder method in LFS at the moment, so what we currently have is a compromise between the two.

This is how I understand the problem, however, I may be completely and utterly wrong.

Shameless selfquote, but I think it's correct:

Quote from AndroidXP :

No, I think it's two different problems, with lag encouraging one of them to appear. First is body intersection, where LFS seems to want to separate the bodies by applying a force just high enough so the intersection is gone in the next collision detection cycle (which runs at 100Hz, I believe). This happens mainly if cars lag into each other, shooting both off into the opposite direction. Some objects seem to have the same basic reaction, but the force is obviously dampened to make them soft (barriers, tyre stacks).

The second, very specific problem is when the contact patch of one of the tyres starts intersecting with an object. I think LFS always tries to put the tyre on top whatever it intersects with, which is okay for bumps on the road, but has quite spectacular results if the "bump" happens to be a red-white barrier. The force calculated from a height difference of a metre within one frame does the rest.

Example 1: South City sideways slide into wall. The tyres on the impact side start intersecting briefly with the wall, generating a short force spike upwards on that side of the car, which is why it always results in a roll "away" from the wall.

Example 2: Red white barriers. These suffer greatly from both problems, with the main quirk being that they are "soft", but at the same time unmovable. Soft alone usually means that with enough force you can drive through them, because the counter-force is not 100% of what is needed to separate the objects, which in the case of tyre stacks is barely noticeable as they're shot off themselves. The barriers however stay put, making it much easier for you to overcome this repellent force allowing you to pass through them with relative ease. For "shortcut" purposes it is generally enough if you have enough speed to make the car pass through the barrier halfway, because as soon as you're through more than 50% it starts shooting you off into the direction you actually want to go.
But with passing through objects, there also comes the risk of your tyres intersecting with it during a collision detection cycle, which is the reason you can only pass "safely" through them with a certain speed, and also explains why the reactions of passing through are seemingly random. Just as an example, imagine we barge through a barrier with 100km/h, which is 27.7m/s, which at 100Hz means that the collision detection makes a check every 27.7cm of car movement. Now picture a side view from the car, drawing a line every 27.7cm. If one of these lines intersects with one tyre's contact patch, you'll fly off, or if it's barely touching, suffer from suspension damage. Of course you cannot calculate a perfect passing through speed with this for each car, because the first line is not necessarily drawn at the front of the car, but can be placed randomly within the first 27.7cm of it, depending on how long ago the last collision check ran when you started intersecting the barrier.

Easy to analyse? Yes. Easy to solve? No.

Quote from Scawen :

In short, don't worry, in the next bunch of physics changes I will be looking at improvements to the collision system.

thanks, in my opinion I love the way you work, i never have seen a developer answer to an user until I looked this forum, this touch my hart so deep.

Solutions:

1) Somebody could build a time machine and go back in time to tell ID Software that telefragging is neither fun or cool. The future will change and meanwhile John Romero's Daikata will be the best game ever.

2) Learn to drive without crashing.

3) Upgrade your 28k modems.

4) Learn to drive without crashing.

5) Srsrly d00ds, my only +1 in this thread goes to 'learn to drive' comments.

Quote :

2) Learn to drive without crashing.

We are trying at all races.

Quote :

3) Upgrade your 28k modems.

Spain is very very very bad in communications, but we are at all with at least 1 MB ADSL and pings of 63 - 78 with our servers.

Quote :

4) Learn to drive without crashing.

Isn't the same to " 2) Learn to drive without crashing" ?

Quote :

5) Srsrly d00ds, my only +1 in this thread goes to 'learn to drive' comments.

Ok, that's your comment.


See ya !!!

Thanks Becky!
Also I just post yesterday the AndroidXP explanation at our league forum at LFS-Spain but I think many people didn't fully understand it cause it's quite technical (although it's very well explained). Thanks to you too dude!

I've read some stuff those days (while I was searching this forum to avoid posting repeated stuff on this community-level-thread) about the collision system working with some type of ray implementation.

So it's just a problem about increasing the rate the collision system works at (with the decreasing of performance associated ) or maybe it could be fixed in some way (or at least minimize the flying2theMoon effect) without changing the system entirely neither increasing the 200Hz rate? (just a minor patch, don't know if I'm making you understand what I want to say :schwitz

Thanks for helping me seeing the light!

Quote from AlfaLover :

Or
Scawen could not fix number 1 , and people learn to fix number 2.

You can fix your 2, but not my own. In other words, you only can drive for your self, not for others.

Quote from kanutron :

You can fix your 2, but not my own. In other words, you only can drive for your self, not for others.

so i take it you have never helped another lfs driver (spannish or not) drive a track faster or wiser? i think hammilton helps alonso all the time

+1

maburroooos! +1

Quote from dadge :

so i take it you have never helped another lfs driver (spannish or not) drive a track faster or wiser? i think hammilton helps alonso all the time

No man, all that I want to say is not means if I'm the best driver of LFS aver the world, never touching fences or even do not any mistake when racing if, another racer slighty hits my side and I go to fly so far away (in a unrealistic way).

And I heleped other (specially not spanish drivers) to drive best at some combos. ;-)

Ah, and its Alonso helping Hamilton all the time, man! :P

I'm arriving a bit late, I see the situation quite clear, but still want to put my 2 cents to the discussion...

First I would post a "+1".... a plus one Licensed LFS user who would love to have that bug fixed. That is, I believe, the meaning of the +1.

I agree it may seem stupid to see x30 times posted but it's the result of a combination of car/track plus about 5 divisions of 32 drivers (lower divisions are filled by lots of newbies or low skilled guys, a matter of TALENT or less time to practice) anyway, resulting in a bigger number of car2airplane testing issue. I can gaurantee that in top divisions of our league this issue did not worried too much. But even if you're an alien, there will be a time when you hit a barrier or other driver do, fly away and ruin your enjoyment and others' if it happens in first laps. It's enough one time to shout shit and low some points the respect for this sim, which is by now for sure the best sim I ever played, and will still be paying with or without this bug.

If this combo had happened two years ago with a 3rd of the people racing, you wouldn't have seen this freaky spanish armada invasion...

I don't know the cue of bugs to be fixed, as I have few spare time, I prefer to use it practicing and enjoying rather than reading forums, but what this post has claimed from the begining, is the vote to put this bug in top of the list.

As Scawen has cleared it is in his mind to fix it, I feel my suggestion is took and I will, with even more emphasy, support this project.

Ah, so we the spanish freaky armada can return to our caves and keep crashing ourselves till the end of times. It's an ofence the lack of respect from many senior members, which sometimes don't tolerate any suggestion, overprotect devs and seem to have in mind that for any reason a country like Spain is just in a lower world. I've seen this also in other forums and in real life, it's disgusting at some points.

Thank you LFS developers, and the great LFS community.

Quote from kanutron :

No man, all that I want to say is not means if I'm the best driver of LFS aver the world, never touching fences or even do not any mistake when racing if, another racer slighty hits my side and I go to fly so far away (in a unrealistic way).

And I heleped other (specially not spanish drivers) to drive best at some combos. ;-)

Ah, and its Alonso helping Hamilton all the time, man! :P

Do you have a special spanish version of LFS, or what?
You dont fly far away if another racer bumps into you, youre just exaggerating.

Quote from Nargaal :

Do you have a special spanish version of LFS, or what?
You dont fly far away if another racer bumps into you, youre just exaggerating.

Imagine a 32 car race... Imagine one of the first cars touching smoothly a wall... Now imagine this car bouncing back and a chain reaction. If you have luck you will be able to see a wonderful massive spectacle of aerobatics.

You're involving too much imagination. When you "smoothly" touch a wall you don't bounce back...

I have a message to Spain: In real life, if we are racing and you bump my car, when the race is over I will kick your ass!

LEARN TO RACE CLEAN. THIS ISNT BUMPER CARS

Quote from AndroidXP :

You're involving too much imagination. When you "smoothly" touch a wall you don't bounce back...

Maybe you don't... I do

P.S.: Try SO box line... There is a shorcut between pits and road. Try to touch (as smoothly as you can) that curb and not to fly...