The chicane coming off the oval section has some very strange behavior.
The suspension of the car gets damage even if you go over the curb very slowly. There seems to be an invisible bump or raised curb on part of this section that makes the car bounce way up. Watch the replay and you will see the car hopping all over the place when driven very slowly over this section. Also notice that the suspension gets damaged while doing this.

It looks to me that the reason for this is the curb is higher then the track of the ther side of the curb. Also like it at blackwood chicane.


OFF TRACK CURB TRACK
_______
________________________| \________________________

Best way i can think of describing what i mean. I may be wrong though.

Actually, it's like that, atleast from the modelling. Maybe the collision mesh (that is different than the track) really has a 90° edge.

The problem is that LFS only has one contact point per tyre. That way, the tyre first intersects with the curb, until the contact point reaches the steep / Then it tries to climb up there, naturally having severe problems doing so, climbing up and falling off the ledge rapidly. This registers as extreme accelleration forces to the suspension that gets damaged, atleast on some cars.

When trying to slowly climb up the ledge in LFS, you suddenly have to drive up a steep angle where you of course don't have any grip, causing you to immediately slide down again. In RL you couldn't even get such a "steep angle contact area", instead you have multiple contact points. See attachment.

You probably have it right there with the contact patch. But there is something wrong with the curb too. The picture shows both rear wheels off the ground. That happened while I backed over the curb at very slow speeds. The curb seems to be much higher than it is shown. It also happens on either side of the curb, front or back. It is not something that is isolated to the back side of the curb like it is for the Blackwood chicane.

However, if what you describe is true, it basically makes the XRR undriveable on KY3. You can't compete with that car unless you take some curb in the chicane. Every time you take some curb there, your suspension gets damaged. It becomes significant after just a few laps.

Very good point Hallen. Nice Spy.

Android i LOVE ilustrations.. of what ever.. as long as it descripes something!

More details about LFS tyre bug:
http://www.lfsforum.net/showthread.php?t=2192

specially this pic
http://www.franknaggies.com/download/lfs/lfs_tyrebug.jpg

So does that mean there should be some re-coding, allowing more than one point of contact?

I also love those illustrations describing the jargon great stuff.

Here is some more video to support the single point of contact issue.

This curb is a bit different. You can see the lip on this curb.

It makes it look like the car is nervous or something

Watch near the end where I try to drive out of it. Pretty funny.

PS, Use shift-U to get the best view.

appart from the problem at hand, i bet it's a nice massage machine you found there

Quote :

So does that mean there should be some re-coding, allowing more than one point of contact?

Perhaps, but that kind of operation is slow to calculate so it would raise the minimum system requirements of the game if it was updated.

I suspect LFS has to do this calculation on all the remote cars too because if it (I suspect) inter-relates with the cars physics then the calculation must be the same on both machines - even if vehicles a long way from the camera are not updated visually, the calculation would need doing from a physics point of view.

As the physics update 100 times a second, adding more polygons for each tyre, there being 4 tyres on each car ... it could add an exceptional load to the processing of the game.

20 cars x 100 calculations x 4 tyres x 3? polygons = 24000 polygons to calculate versus 8000.

Of course a lot of this is dependant upon the internal calculations of the LFS engine, certainly the visual aspect only needs to be updated once per frame per tyre and only on tyres near to the camera. If this isn't effecting the cars actual physics (which it seems is not the case and that this is directly used by the physics system) then calculating multiple polygons becomes a horrendous number crunching exercise.

You could make multiple polygons handled only by the local machine and deal with remote cars as a single polygon, but this could cause jittering as remote cars go over kerbs and bumps in the road and significantly destabalise the network code.