The online racing simulator
About the laser scanned track....
To save me reading 50 odd pages and possibly still not finding the answer, could some kind person tell me if it's known whether or not Rockingham will have the same level of surface detail (bumps, lumps and contours) as iRacing tracks have?

It's the single thing that puts iRacing in a class of its own IMO.
It will probably have a pretty good surface detail but unfortunately LFS' FFB will filter most of it out so it will still feel bland compared to other sims.
Quote from obsolum :It will probably have a pretty good surface detail but unfortunately LFS' FFB will filter most of it out so it will still feel bland compared to other sims.

You say that like a bad thing, though I suspect you don't mean it as one. I agree though that most of the bumps etc wont be noticed so much due to bumps being felt through your bum not through the steering wheel which ofcourse lfs doesn't simulate.
Quote from obsolum :It will probably have a pretty good surface detail but unfortunately LFS' FFB will filter most of it out so it will still feel bland compared to other sims.

Only if you expect gimmicky and unrealistic shaker effects.

The scanning process is very complex. The machines used are very expensive, usually in the $70k-$80k range. They have the ability to shoot thousands of points per second. Their accuracy will vary with range and angle to the object being measured. The technology is basically time of flight where the amount of time it takes the light to leave the instrument, hit the target, and bounce back to the instrument is measured and then the distance can be calculated. Or, it can be a phase measurement system that basically counts the whole number of waves that it takes to reach the point.

Depending on the process, special targets are placed in the area to be measured. Those targets are shot form at least two different locations. Then the targets can be used to stitch together the measurements from various locations.

An example of the type of instrument that could have been used is here:
http://www.trimble.com/trimblegx.shtml

People can claim that the process will produce measurements within 2cm, and that is reasonable. However, the instruments themselves can measure more close than that, down into the mm range, but because of variances in setups, temperature, length of shot, visibility conditions, etc, getting that level of accuracy across an entire job site is difficult. If the proper care is not taken, you can end up with points that are off by quite a bit. Lets say your stated accuracy is plus or minus 2cm. That means that any given point could be 2cm too high and the point right next to it could be 2cm too low giving a pretty big bump. There are techniques to improve this of course, but it is extrapolation, not actual.

So, even the vaunted iRacing scanned tracks are not going to represent every bump accurately. Any trend, like a slope, or bigger bumps like you would find at Sebring, can be modeled pretty well. But small bumps, or sharper bumps will most likely get lost. So, it's true when they say they are accurate within 2cm, but realistically, they are not really that good. A lot of additional measurements would have to be taken using different instruments to get things really close, and that kind of thing would probably be prohibitively expensive.

I know, more than you wanted to know, right?
Thanks for the links ATHome and dekojester. Still not sure how much surface detail there'll be though.

The surface irregularities have a big effect when driving at the limit. iRacing tacks require a lot of extra attention to inputs from steering (small corrections) and throttle to get yourself around. It's a completely different driving experience to the flat tracks in other sims. And you do feel irregularities through the wheel too.

As far as iRacing's tracks' real life accuracy, I couldn't know and don't actually care that much. But a number of people who do have claimed they're spot on.
remember as well the devs didn't pay. Rockingham did. So it depends on the quality of the laser scanning company they used too.
Quote from Luke.S :remember as well the devs didn't pay. Rockingham did.

Is this true?
Quote from Matrixi :Is this true?

Don't know if Rockingham payed, but as far as I know the devs did not pay indeed.
Quote from Greboth :You say that like a bad thing, though I suspect you don't mean it as one.

I did mean it as a "bad" thing

Quote from Greboth :I agree though that most of the bumps etc wont be noticed so much due to bumps being felt through your bum not through the steering wheel which ofcourse lfs doesn't simulate.

I've seen many people say that when LFS' blandness is brought up, but I find I actually do feel bumps through the steering wheel in a real (road)car, especially if I'm driving it in a sporty manner. I'm glad Postman Pat confirmed this in his post

Also, it's not just about "feeling bumps through the steering wheel", there's just something about LFS' "feel" that makes it unbelievably dull to drive; I don't feel connected to the car or the road at all.
Quote from Hallen :So, even the vaunted iRacing scanned tracks are not going to represent every bump accurately.

As you said, the equipment can measure much better than 2cm. Whether it's true or not I don't know, but iR stated accuracy in the mm range at some point in the past.
Quote from obsolum :
Also, it's not just about "feeling bumps through the steering wheel", there's just something about LFS' "feel" that makes it unbelievably dull to drive; I don't feel connected to the car or the road at all.

That's due to Soapy tires. Isn't that why he's fixing the physics for them? :3
TIP: Go Rockingham on this Saturday/Sunday, And it will most probably be there.
Quote from obsolum :I've seen many people say that when LFS' blandness is brought up, but I find I actually do feel bumps through the steering wheel in a real (road)car, especially if I'm driving it in a sporty manner.

This is more of a limitation of force-feedback itself rather than the software engine used to control it. At present, the FFB system in a wheel can only pull the wheel from side to side to simulate forces at the steering rack (which LFS reproduces). What's missing are the forces coming through the steering column from the chassis which bash your hands about - a motor moving the wheel forwards and back is needed to get this.
Quote from Ball Bearing Turbo :As you said, the equipment can measure much better than 2cm. Whether it's true or not I don't know, but iR stated accuracy in the mm range at some point in the past.

Yep, but like I said, you can quote the accuracy of the equipment on a single, perfect measurement, but that certainly does not indicate what you are actually going to get. There's a lot more that goes into it, I can assure you of that.

I'm not trying to dis iRacing tracks. I'm just saying that they will not capture everything, even with a scan.

Scanning is awesome and there is no better way to get a track into a game, given the current technology. I'm all for it. I'm just saying it isn't perfect, it has to be done right, and you can easily over-state the accuracy.

Even at 2cm, you are going to get a very good representation of the track. The edge of the pavement will be blended a bit. Curbs will probably need some touching up, etc. But by saying you scanned it simply does not mean it is a perfect representation. It's close, but some fudging will have to be done.
Quote from Hallen :Yep, but like I said, you can quote the accuracy of the equipment on a single, perfect measurement, but that certainly does not indicate what you are actually going to get. There's a lot more that goes into it, I can assure you of that.

I'm not trying to dis iRacing tracks. I'm just saying that they will not capture everything, even with a scan.

Scanning is awesome and there is no better way to get a track into a game, given the current technology. I'm all for it. I'm just saying it isn't perfect, it has to be done right, and you can easily over-state the accuracy.

Even at 2cm, you are going to get a very good representation of the track. The edge of the pavement will be blended a bit. Curbs will probably need some touching up, etc. But by saying you scanned it simply does not mean it is a perfect representation. It's close, but some fudging will have to be done.

I understand what you're saying, I'm just wondering how/if they've gone to lengths to make sure they're getting max possible accuracy wherever it's important - the surface.

They've said so in the past numerous times, such as:

"Iannarelli, whose professional responsibilities at iRacing.com include sound recording, track building, car scanning and collection of vehicle engineering data, noted that when he and his colleagues complete the build process, the finished virtual version of the track will feature millimeter accuracy. “A lap of the virtual track is exactly the same as a lap of the physical track. When you’re racing at Thompson on our internet service, you’re really racing at Thompson.”

Based on what they've always stated, the delta is much less than 2cm with whatever method(s) they're employing. Maybe they're lying, I don't know, but the tracks feel very, very good.
I don't know what you people think but I'd expect the Rockingham patch to have a revised (unfiltered?) FFB. Otherwise I see little point in having a laser scanned track and thus little point in spending money on it.
Quote from Ball Bearing Turbo :I understand what you're saying, I'm just wondering how/if they've gone to lengths to make sure they're getting max possible accuracy wherever it's important - the surface.

They've said so in the past numerous times, such as:

"Iannarelli, whose professional responsibilities at iRacing.com include sound recording, track building, car scanning and collection of vehicle engineering data, noted that when he and his colleagues complete the build process, the finished virtual version of the track will feature millimeter accuracy. “A lap of the virtual track is exactly the same as a lap of the physical track. When you’re racing at Thompson on our internet service, you’re really racing at Thompson.”

Based on what they've always stated, the delta is much less than 2cm with whatever method(s) they're employing. Maybe they're lying, I don't know, but the tracks feel very, very good.

Ignorance is bliss. Seriously.
Against what datum are they measuring their "accuracy". I doubt the guy who does sound recordings, etc, knows one way or another. Unless you are a professional who does this kind of stuff regularly, you aren't going to know.

I doubt they are lying, they're just not stating all the facts. Listen, I'm not making this stuff up. That link I put a few posts ago... that's who I work for. I don't sell the scanning stuff, but I do know precision field measurements. If the instrument says plus or minus 2mm distances, which is reasonable, it doesn't mean squat if you vertical is out or if your calibration is off, or you measure at too oblique of an angle or... the list goes on. I can also guarantee they will not move that instrument and do more setups than is absolutely required to get the minimum data to do the job. It's just a fact of economics and time.

I do know a few things about this kind of work. Believe what you want. I could be wrong and they could be the most perfect field surveyors in the world.
Quote from Hallen :I can also guarantee they will not move that instrument and do more setups than is absolutely required to get the minimum data to do the job. It's just a fact of economics and time.

That's the only part of your post that may or not be true.

They do tend to take a lot longer than LFS stated to scan one small measly oval track, based on their published records.

It's not a fact of economics and time, unless you're in charge of their economics and time

They still could be lying.
#21 - Jakg
Quote from Matrixi :Is this true?

While it's never been mentioned, Scawen has made it very very clear in the past he objects to pay to advertise someones track or car in the game. For this reason all the previous cars were added in exchange for advertising, i'd imagine Rockingham is no different (making his own game and company means he can stick to his principals as he shows a lot)

Quote from obsolum :I find I actually do feel bumps through the steering wheel in a real (road)car, especially if I'm driving it in a sporty manner. I'm glad Postman Pat confirmed this in his post

Perhaps the car has something to do with this? My car, with its large wheels (18") and low profile tyres makes me "feel" a lot more bumps simply because of physics, that I wouldn't feel with the 14" wheels on my old car, that doesn't mean it's more responsive, just that the wheel tramlines a hell of a lot easier.

Most track cars use 13-15" wheels, whereas most road cars use overly large wheels that look good - perhaps this makes you feel more "connected"?
Quote from Luke.S :remember as well the devs didn't pay. Rockingham did.

I've never seen anything saying this. Please don't make stuff up.
Quote from Bob Smith :I've never seen anything saying this. Please don't make stuff up.

I was going by past examples and presumed that it would be the same for tracks.
BTW in the Rockingham page that was linked above, it clearly states it was them to contact and arrange stuff with the scanning company.

It doesn't necessarily mean they have paid for it, but it seems a reasonable enough assumption?

But, paying for scanning and paying for licensing are two entirely different things.
The real question is not how accurate the 3d scanner is ( 2cm or less some say ) but how many measurements are taken for one square meter of the track.
1

FGED GREDG RDFGDR GSFDG