Quote from Shotglass :

parallel vector processors are quickly being introduced into the pc market so while i wouldnt hold my breath chances are by the time s3 comes out a parallel coprocessor which should easily chew through ror magnitudes faster than any current cpu might be standard in pcs

Yes but you need to cater for the majority of the user base so you have to add about 3 or 4 years on after the technology becomes widely avaliable (and standard in everyday PCs) before you can cut off the slower machinery. So a non-rigid physics model isn't going to happen in S2 and presumably not in S3 either, based on the guess that S2 will be final this time next year and S3 will appear about 2 years afterwards they'd still not be a feasible option for S3 (in the beginning at least)

The reason transport trucks twist and flex like that is so the frame can handel the forces without breaking. If you've ever seen a transport truck on the company's test track. It articulates alot more than what you'd normaly think, you can get as much as 10º of flex front to back if not more.

All vehicles have some amount of body flex, some more than others.
Otherwhise they'd snap under heavy stresses.

If you made a completely rigid body or frame that didn't alow for some small amount of flexing, it would be to fragile. When something gives it has a tendancy to absorb energy and transmit it across it's surface, if it doesn't do that than the energy would be focused completely onto the point of impact. If this where on a transport truck, anything that takes a shock during a bump in the road would eventualy suffer from material fatigue and break.

I think there is a better solution for chassis flex than calculating the whole thing with physics, but I don't have time to come up with a reasonable solution.

one idea would be to have a pre set motion range for the four corners of the car and have curtain forces push them a given amount. It's not going to be 100%. but it will give you some form of flex without having to calculate it completely. This could be implamented untill LFS's phyics engine is capable of running physics on multiple threads.
After that, a more realistic one could be devised.
Edit: this doesn't have to be visible. since that would require alot of work to adapt the models.

Body flex, as I understand yall's intended iteration, is only really noticed in older vehicles and convertibles in real life, and the majority of vehicles that have it are Body-on-frame vehicles. Unibodies don't seem to suffer from it all that much, for the most part(Convertibles the exception)

Take, for example, the bed and cab of my 1985 F150. The bed flops about so much that if you stare at the gap between the bed and the cab through the split rear window, you can see it moving with your own eyeballs. It moves far enough to nearly close the inch-and-a-half gap Ford put there. It's 2007 replacement, however, needs a 200FPS camera minimum to pick up the flex between it's bed and cab, and this allows Ford to close the gap between these two parts considerably.

Newer cars are made stiffer, to improve handling greatly. They don't really flex at all. They only really flex when you hit something, whether it a pothole or another car.

The flex that would be most against handling, to the vehicles the game currently has, is actually called chassis warping. Gran Turismo has had it for a while, and altho not at all visible(Vehicle shapes remain perfect), the handling goes to shit after about 15,000 miles, and then you must purchase a repair to get it to handle right again.

If car mileage was included in LFS, there would be a simple calculation that based grip on the front and grip on the rear against miles on the car, with more miles producing more grip loss. Wouldn't even need calculation in real time, but instead could be calculated when the game is saved, or when the car is pitted, for on-the-fly adjustments to the handling. All it needs is the equation set created and the mileage counter implemented and we have a body warping setup that wouldn't cause any performance issues to the computer.
Some vehicles would have a more sensitive equation than others, for example, the Cabriolet's would warp alot easier than the F1 or hatchbacks, which are the hardest to warp.

The kind of flex required to accurately simulate body flex on older vehicles/pickups is a moot point ATM, since LFS has neither of these. All it has is newer unibody-based autos.

I, for one, wouldn't really mind the minor unrealistic lack of body flex if LFS started packin' some pickups either. I just love trucks, and love trying to defy the laws of physics with them in video games, of course.


And regarding RoR, that game is a bit of a showoff of the physics engine. I've coded cars for it myself. One is a small FF sedan, the other a futuristic 6X6 desert truck. Both of them behave like springs when you hit something. I've also got a series of screenshots of the skinned and textured sedan passing right through a pole without touching it. Realistic, isn't it?

Quote from Electrik Kar :

Just wondering why karts flex more than other cars? Is it a softer undertray or something that helps with suspension?

carts don't have suspension, their tube-frame chassis bends, and in doing so, picks up the inside wheel in a turn, to make steering easier for example. The chassis really acts as the suspension. That's why karting frames may "look" good, but really should be replaced every ear if you have a good budget and are a top competitor.

Quote from tristancliffe :

Circular metal tubing, of similar dimensions, is weight for weight STRONGER and STIFFER than square tube. That is why roll cages are round...

Cars aren't made of out square tubing anyway - they are a monocoque construction these days, where the skin, rather than separate tubes, carry the stresses.

So, a lotus, which is TECHNICALLY a monotube car, is still like this? No! Or the corvette? No. It depends on how the chassis is designed.

Funny you should mention it slamdunk.

First thing i thought of while reading RoR was that i nearly froze my last computer by showcasing all the verhicles and theyre capacities in one screenshot.
Well.. almost all as the "rubber bands" mentioned before kept on swaying and dropped the fps from about 27 slowly but surely to 2..
and it took very long for sure.. hehe. Cool playingtoy btw that RoR.

I guess it would make a decent framehit to have everything hang loose, but.. who knows what's possible in the future, good suggestion.. (now i'm thinking doors hanging on one hinge and beeing dragged by the car.. hehe.. exhausts dangling under the car touching the ground as you have been catapulted over a curb.. )

Regards
Frank

Quote from Mako. :

So, a lotus, which is TECHNICALLY a monotube car, is still like this? No! Or the corvette? No. It depends on how the chassis is designed.

A Lotus what? An Elite, Eclat or Esprit has a backbone chassis, which is a large square tube. But it's NOT a stressed body car. The Elise/Exige is also an unstressed body car, with the loads passing through the bonded aluminium chassis.

Not many Lotus have been monocoque chassis (that I can think of).

Ah, I think I've just translated your incredibly poor English. You mean that some cars remain tubular, don't you? I wondered which smart ass would try and correct me. Well done. Yes, lots of cars remain with tubes, but they are either expensive cars (Lamborghinis, Corvettes etc) or [relatively] small volume cars (kit cars, Sevens, Lotus, Radicals, Ariels etc).

The VAST majority of cars and race cars are monocoque construction, and it was to this majority that I was referring.

Quote from ajp71 :

They would all suffer from body flex, there's a reason why an F1 car is 600 times stiffer than a typical road car

Once again I draw your attention to the original post, asking for visible body flex. I'm not stupid. When I said noticeable body flex in my first post, it's in the context of it being visually/graphically modelled, which is what he's asking for. Something which I see absolutely no point in whatsoever, because none of the cars in LFS would noticeably flex unless you looked very, very, very closely.

Of course LFS should model flex in the physics way, that's not the debate though is it?

Quote from sinbad :

Once again I draw your attention to the original post, asking for visible body flex. I'm not stupid. When I said noticeable body in my first post, it's in the context of it being visually/graphically modelled, which is what he's asking for. Something which I see absolutely no point in whatsoever, because none of the cars in LFS would noticeably flex unless you looked very, very, very closely.

Of course LFS should model flex in the physics way, that's not the debate though is it?

I hadn't realised you were talking about visual representation of flex, which would be pointless

Well, to tell you the truth, I wasn't really asking for just visual representation because, you know, (almost) everything in LFS comes, and should come, from physics so of course the flex would have to realistically affect everything that it is supposed to.

Maybe you were reading a bit too much into the last paragraph in the OP

Quote from tristancliffe :

A Lotus what? An Elite, Eclat or Esprit has a backbone chassis, which is a large square tube. But it's NOT a stressed body car. The Elise/Exige is also an unstressed body car, with the loads passing through the bonded aluminium chassis.

Not many Lotus have been monocoque chassis (that I can think of).

Ah, I think I've just translated your incredibly poor English. You mean that some cars remain tubular, don't you? I wondered which smart ass would try and correct me. Well done. Yes, lots of cars remain with tubes, but they are either expensive cars (Lamborghinis, Corvettes etc) or [relatively] small volume cars (kit cars, Sevens, Lotus, Radicals, Ariels etc).

The VAST majority of cars and race cars are monocoque construction, and it was to this majority that I was referring.

Yeah, sorry, I am from Russia and sometimes my english gets a little confusing. =]

I know conversational english well, but have terrible time writing essays, etc.

I also completely messed up what I tried to say there, but yes, you understood it prefect!

Quote from ajp71 :

RoR shows the limits of current computing power, one or two vehicles in a very low detail system running at an uncomfortably low frequency can grind todays top notch machinery to a halt with very little in terms of non-chassis physics demands.

Hmm, correct me if I'm wrong but doesn't nKPro have chassis flex? Even visible chassis flex? I'm certain I've seen a slow-mo video showing it off. I'm not sure how advanced it is and how much of an impact it has but if nKPro already has it it can't be that processor intensitive? High frequency, sure, but it can probably be simplified a great deal and still give approximately the right results. I doubt a physics model like in RoR would be the only way to implement this.

I don't know if I've ever read anything officially confirming nK having chassis flex but people seem to think it does. My guess is it's simply an extra spring connecting the suspension pickup points giving a vague approximation not really modeling chassis flex. I doubt it's shown visually or simulates a full spaceframe chassis RoR style because it doesn't use that much CPU and there's no deformation damage.

hehe, it's not easy coming up with a new idea in this community

here is a thread on the same topic from June 2006. There are posts from both Scawen and the guy who made ROR !

it makes for interesting reading!

Quote from ajp71 :

I don't know if I've ever read anything officially confirming nK having chassis flex but people seem to think it does.

Yeah, I spent a few minutes searching RSC and I couldn't find anything but a few people thinking they saw chassis flex. Maybe that's where I got it from.

Anyway, I should think an approximation of sorts could do the job pretty well in LFS. I don't see the need to go directly to a complex model like in RoR and spend 3/4 of the processor budget on the chassis. The tyres are already very rough approximations, and they work fairly well.

I think there was a video out which focused on the wings, saying they were flexing. But everyone who saw the video was like 'what flexing?'. I couldn't see it myself.

I think it's quite enough if each car were split in the middle (front vs rear) then joined together using a spring/damper ball joint. However, I'm not sure if the required frequency will be too high. I guess it'd be a bit better than RoR, since about the same force is applied on two 600kg pieces instead of 10kg nodes.

Quote from tristancliffe :

A kart needs the flex because it DOESN'T have 'suspension' as such (i.e. no springs, dampers, rockers etc), and thus relies on the controlled 'give' of the chassis to provide compliance. Without chassis flex a kart would be undriveable. It's absolutely required.

I'd say all vehicles require some degree of chassis/frame flex otherwise apart from undrivable or highly uncomfortable they'd also simply eventually break.

Quote from xaotik :

I'd say all vehicles require some degree of chassis/frame flex otherwise apart from undrivable or highly uncomfortable they'd also simply eventually break.

Yup, it's why brazing a chassis is far better (for kit builders) than a MiG or TiG weld, as the braze is strong but has some give. A GOOD TiG or MiG weld is theoretically stronger, but much harder to acheive (and looking good doesn't count) than a decent braze.

For some reason brazing a chassis, despite the above, is not allowed in UK Single Vehicle Approval, because it's written by idiots in suits that don't really understand what they're talking about

Bumping this old thread, to mention this great game once again!

Was watching youtube here the other day, and came across videos like this:
http://www.youtube.com/watch?v ... R=1&feature=endscreen

I don't think I have ever seen a game simulate damage that well, it's amazing! This game also have an online mode - but have not tested that one out. Demands a shitload of CPU power btw!

Any experiences / thoughts about this game?

I love the flexibody there, but it demands too much CPU power (more than I have).

Quote from The Very End :

Bumping this old thread, to mention this great game once again!

Was watching youtube here the other day, and came across videos like this:
http://www.youtube.com/watch?v ... R=1&feature=endscreen

I don't think I have ever seen a game simulate damage that well, it's amazing! This game also have an online mode - but have not tested that one out. Demands a shitload of CPU power btw!

Any experiences / thoughts about this game?

u cant interact with other players vehicles. only ur own vehicles.

but if u have an decent computor it works good with some ppl on it..

Also, a kart has some empty space behind the front wheels.

The chassis at that point is about 300mm wide.

Cars do not have that. It contributes a ton to the flex the chassis has.

Oh, then the multiplayer sucked, belived you could hit others
About the game, it's too damn demanding for mye PC, so I have just barely tested it out.
Still, crash porn!

Quote from Mr_Lonely :

u cant interact with other players vehicles. only ur own vehicles.

but if u have an decent computor it works good with some ppl on it..

Quote from The Very End :

Oh, then the multiplayer sucked, belived you could hit others
About the game, it's too damn demanding for mye PC, so I have just barely tested it out.
Still, crash porn!

Depends on which version you're on. There was a version where you could crash into others and even lift people.

With the arrival of 0.39, which is currently tested, it should run really fast on modern PC's with more than 2 cores.