LFS blues....I play LFS...
1- because the noise of paddles makes my wife crazy and prevents her from sleeping... my only pleasure in life.
3- because now my wife left me, the sound is strong enough I can't hear the children crying for food
2- because now I started drinking, the police took my license
4- because now the tax office took the good computer, LFS is the only game still running on a pentium 120 mhz.
5- because now I am in jail, when I play LFS once a month I feel like I am outside.
1- because the noise of paddles makes my wife crazy and prevents her from sleeping... my only pleasure in life.
3- because now my wife left me, the sound is strong enough I can't hear the children crying for food
2- because now I started drinking, the police took my license
4- because now the tax office took the good computer, LFS is the only game still running on a pentium 120 mhz.
5- because now I am in jail, when I play LFS once a month I feel like I am outside.
Thank you for progress report! 2011 should be good for LFS 
It is not the friction of rubber for different sliding velocities, it is a measure of max lateral/longitudinal friction coefficient of the tyre for different velocities of the vehicle. Not so easy to find....most benchmarks are performed at constant velocity.
You can see in this document the load sensitivity of friction is more linear than expected (from a rubber block), at least for the lateral friction. Quite logical if we think the tyre contact patch is always between stiction and friction.
Even for very large slip angle, as the tyre is rolling, the rubber from the contact patch is "renewed" all the time and this "new" rubber, before fully sliding, first sticks and deforms.
As a result, it seems to me the behavior of a tyre (not locked) is always more stable, more progressive than the rubber block. Don't know if I am clear. In fact I know I am not
You can see in this document the load sensitivity of friction is more linear than expected (from a rubber block), at least for the lateral friction. Quite logical if we think the tyre contact patch is always between stiction and friction.
Even for very large slip angle, as the tyre is rolling, the rubber from the contact patch is "renewed" all the time and this "new" rubber, before fully sliding, first sticks and deforms.
As a result, it seems to me the behavior of a tyre (not locked) is always more stable, more progressive than the rubber block. Don't know if I am clear. In fact I know I am not
Last edited by Juls, .
Uh, sorry you are right, picked the wrong document
Here is the doc with actual measures. I uploaded it because I can't find any link to it anymore.
http://www.megaupload.com/?d=KDME226O
Load sensitivity (figure 4.6, 4.10,4.14, 4.18...E.2, E.3, E.5, E.8, E.9, E.12, E.13, E.16, E.17) is almost linear, with high friction coeff for low loads....never a convex shape like in ISI-based sims tyre files (assuming the three coeffs are what they are said to be in the comments).
I dare to hope they have more than 2 points of measure and don't call "measure" model-fitted data
BTW this document has other valuable things, like the speed sensitivity and the stiffness...pretty hard to find.
Amazing how tyre grip falls quickly with velocity...ISI-based sims use less dramatic values there too.
Here is the doc with actual measures. I uploaded it because I can't find any link to it anymore.
http://www.megaupload.com/?d=KDME226O
Load sensitivity (figure 4.6, 4.10,4.14, 4.18...E.2, E.3, E.5, E.8, E.9, E.12, E.13, E.16, E.17) is almost linear, with high friction coeff for low loads....never a convex shape like in ISI-based sims tyre files (assuming the three coeffs are what they are said to be in the comments).
I dare to hope they have more than 2 points of measure and don't call "measure" model-fitted data
BTW this document has other valuable things, like the speed sensitivity and the stiffness...pretty hard to find.
Amazing how tyre grip falls quickly with velocity...ISI-based sims use less dramatic values there too.
Last edited by Juls, .
Tyre load sensitivity (last chart in the document) for two unknown tyres, showing a straight line and a very important grip at low load.
http://www.optimumg.com/Optimu ... chTips/TireComparison.pdf
http://www.optimumg.com/Optimu ... chTips/TireComparison.pdf
You say that because you were born in a democracy. You know the sentence...it's ugly, but everything else we have tried before is deadly.
But anyway...closing threads or not on this forum has nothing to do with democracy. It's property right. It's their forum.
Last edited by Juls, .
Yes Bob...(-3.10e-6, 0.65, 14000.0)
It defines a multiplier applied to friction coefficient, initial value is 1.0 for load 0. First figure is slope in zero.
Second figure is final value for the multiplier, reached for load 14000N.
To rebuild the curve in a unique way, we assume the slope is zero in final value...we can make a 3rd degree polynom from that.
Other possibility is to make a 2nd degree polynom if you don't care about slope in last value.
Both curves rebuilt give very convex shapes. From real data and many publications, the curve is almost a straight line...slope should be constant...but rebuilt curves from sim data are very different...slope is 10 times lower than real data first, and only reaches real data value beyond load range a tyre will cover when used in normal racing condition (almost 3 times static load).
Comparing 2nd degree curve with straight line from real data gives bigger difference...12 times lower sensitivity at 0N, 5 times lower at half static load, 3 times lower at static load....curves cross each other at 11000N.
It defines a multiplier applied to friction coefficient, initial value is 1.0 for load 0. First figure is slope in zero.
Second figure is final value for the multiplier, reached for load 14000N.
To rebuild the curve in a unique way, we assume the slope is zero in final value...we can make a 3rd degree polynom from that.
Other possibility is to make a 2nd degree polynom if you don't care about slope in last value.
Both curves rebuilt give very convex shapes. From real data and many publications, the curve is almost a straight line...slope should be constant...but rebuilt curves from sim data are very different...slope is 10 times lower than real data first, and only reaches real data value beyond load range a tyre will cover when used in normal racing condition (almost 3 times static load).
Comparing 2nd degree curve with straight line from real data gives bigger difference...12 times lower sensitivity at 0N, 5 times lower at half static load, 3 times lower at static load....curves cross each other at 11000N.
Last edited by Juls, .
It is obvious that tyre load sensitivity is how much the tyre friction coefficient changes when load increases. One time again you are confusing tyre load sensitivity with tyre friction for a given load. Sensitivity is the derivate of the friction coefficient according to load.
So when you take this line (-3.10e-6, 0.65, 14000.0)
Tyre sensitivity is the slope of this curve multiplied by friction coefficient, not the final value 0.65. Final value 0.65 is very probable for a real tyre...this is not the problem.
But if you look at the slope...tyre load sensitivity for a real tyre when load is zero is about -3.75e-5, ie 12 times this one above (first value is the initial slope).
And for a real tyre, even if the final value is close from the one above...0.55, the slope is almost constant, -3.75e-5 all the way from 0 to 12000N.
If you compare (-3.10e-6, 0.65, 14000.0) with (-3.75e-5, 0.55, 12000.0), then:
* at 0N, real tyre data gives 12 times more load sensitivity than this tyre.
* at half static load 1500N, real tyre data gives 3 times more load sensitivity than this tyre
* at static load 3000N real tyre data gives 2 times more load sensitivity than this tyre
* It is only at 8000N than this tyre load sensitivity becomes equal real tyre data, and later it increases a lot to give the 0.65 final value.
Looks like nothing, but this changes a lot the tyre behavior. I wrote 10-20 times higher because I was thinking about this line and the slope in zero...but it is definitely 2-3 times higher in normal driving conditions. Here sims and real world data are very different...why?
Yeah I am not such an idiot....surprise...
So when you take this line (-3.10e-6, 0.65, 14000.0)
Tyre sensitivity is the slope of this curve multiplied by friction coefficient, not the final value 0.65. Final value 0.65 is very probable for a real tyre...this is not the problem.
But if you look at the slope...tyre load sensitivity for a real tyre when load is zero is about -3.75e-5, ie 12 times this one above (first value is the initial slope).
And for a real tyre, even if the final value is close from the one above...0.55, the slope is almost constant, -3.75e-5 all the way from 0 to 12000N.
If you compare (-3.10e-6, 0.65, 14000.0) with (-3.75e-5, 0.55, 12000.0), then:
* at 0N, real tyre data gives 12 times more load sensitivity than this tyre.
* at half static load 1500N, real tyre data gives 3 times more load sensitivity than this tyre
* at static load 3000N real tyre data gives 2 times more load sensitivity than this tyre
* It is only at 8000N than this tyre load sensitivity becomes equal real tyre data, and later it increases a lot to give the 0.65 final value.
Looks like nothing, but this changes a lot the tyre behavior. I wrote 10-20 times higher because I was thinking about this line and the slope in zero...but it is definitely 2-3 times higher in normal driving conditions. Here sims and real world data are very different...why?
Yeah I am not such an idiot....surprise...
Last edited by Juls, .
Tuning handling with spring stiffness and anti-roll bar changes the load repartition (and the way it changes during time), and this changes the cornering forces each tyre gives at a given moment.
It works even with a zero load sensitivity.
Don't know if I am clear.
Max lateral force = u*Load-loadSensitivity*Load*Load.
If you take loadSensitivity=0, you still have tyres reacting to load change....change the load repartition during time through suspension stiffness and anti-roll bar and you change car handling.
The load sensitivity is not vital for the basic handling of car, but it makes tyres more intersting. Without it, tyres have only one reason to give up or get back grip...slip angle, lateral force. With it you have two reasons to give up or get back grip, lateral force and load. One is unstable (slip), the other is stable. When you slide more and more the tyre gives up grip because of slip sensitivity, but get some grip back through load sensitivity.
IMO this is the reason why you can drift (slip angle up to 20 degrees or more ) with race tyres which reach peak lateral friction at 8 degrees or less.
It works even with a zero load sensitivity.
Don't know if I am clear.
Max lateral force = u*Load-loadSensitivity*Load*Load.
If you take loadSensitivity=0, you still have tyres reacting to load change....change the load repartition during time through suspension stiffness and anti-roll bar and you change car handling.
The load sensitivity is not vital for the basic handling of car, but it makes tyres more intersting. Without it, tyres have only one reason to give up or get back grip...slip angle, lateral force. With it you have two reasons to give up or get back grip, lateral force and load. One is unstable (slip), the other is stable. When you slide more and more the tyre gives up grip because of slip sensitivity, but get some grip back through load sensitivity.
IMO this is the reason why you can drift (slip angle up to 20 degrees or more ) with race tyres which reach peak lateral friction at 8 degrees or less.
Everytime I see a discussion about tyre models, the main topic is tyre forces vs slip, let's call it tyre slip sensitivity. But what about tyre load sensitivity?
I don't know how it is with LFS, but tyre load sensitivity is strongly underestimated in all ISI/Simbin titles. Recently I could find some real world data showing tyre load sensitivity, how the peak friction coefficient decreases with increasing load. It is 10-20 times more sensitive than in ISI/Simbin titles.
For me the load sensitivity is very important to get accurate tyre behavior, as much as slip sensitivity.
When going sideways, the tyre slip sensitivity (grip slightly decreasing after peak) is responsible for the traction loss and wants to make your car spin passed the peak slip angle. It defines how punishing a tyre is. It is cause of unstability.
But the load sensitivity is very important too. It acts the opposite way as a stability factor and defines how easily you can recover at high slip angles. When you go sideways passed the peak slip angle, the lateral forces decrease (slip sensitivity). The car can't follow anymore the curve, the turning radius increases. Less cornering-> less load on outside tyres-> their grip increases pretty well thanks to the load sensitivity-> you can keep the car sideways without spinning or even recover.
IMO the balance between tyre slip sensitivity and tyre load sensitivity is very important for handling. The load sensitivity is strongly understimated in all ISI/Simbin titles (and no surprise these titles are well known for the punishing spins when you exceed a given slip angle). Another thing...the load sensitivity makes the car alive on track bumps. When you are cornering close from the limit and a bump makes your car pivot this is for me a typical consequence of tyre load sensitivity.
I don't know how it is with LFS, but tyre load sensitivity is strongly underestimated in all ISI/Simbin titles. Recently I could find some real world data showing tyre load sensitivity, how the peak friction coefficient decreases with increasing load. It is 10-20 times more sensitive than in ISI/Simbin titles.
For me the load sensitivity is very important to get accurate tyre behavior, as much as slip sensitivity.
When going sideways, the tyre slip sensitivity (grip slightly decreasing after peak) is responsible for the traction loss and wants to make your car spin passed the peak slip angle. It defines how punishing a tyre is. It is cause of unstability.
But the load sensitivity is very important too. It acts the opposite way as a stability factor and defines how easily you can recover at high slip angles. When you go sideways passed the peak slip angle, the lateral forces decrease (slip sensitivity). The car can't follow anymore the curve, the turning radius increases. Less cornering-> less load on outside tyres-> their grip increases pretty well thanks to the load sensitivity-> you can keep the car sideways without spinning or even recover.
IMO the balance between tyre slip sensitivity and tyre load sensitivity is very important for handling. The load sensitivity is strongly understimated in all ISI/Simbin titles (and no surprise these titles are well known for the punishing spins when you exceed a given slip angle). Another thing...the load sensitivity makes the car alive on track bumps. When you are cornering close from the limit and a bump makes your car pivot this is for me a typical consequence of tyre load sensitivity.
Last edited by Juls, .
Hm yeah my exemple with spring dampers was too simple. I was thinking something like take a simple model like a LUGRE stiction/friction and I figured it would not look simple at all for the reader
I wanted to say something like that: IMO if you really model the tyre/road action/reaction like a stiction/friction mechanism, even a very simplified one, you can avoid many pitfalls.
- some stiction/friction models are robust at speed 0
- they can immediately take into account hysteresis
- they seem scalable and very convenient for object oriented programming
Of course you have lots of experience I clearly don't have. But as a software developer, my feeling is that implementing such model instead of the very usual slip curve model could be a win win situation. Possibly richer model at the end, probably less problems adjusting it, more intuitive. Don't see the problems precisely in advance...but usually I am not too bad guessing which general direction is less crowded with problems than the other
I wanted to say something like that: IMO if you really model the tyre/road action/reaction like a stiction/friction mechanism, even a very simplified one, you can avoid many pitfalls.
- some stiction/friction models are robust at speed 0
- they can immediately take into account hysteresis
- they seem scalable and very convenient for object oriented programming
Of course you have lots of experience I clearly don't have. But as a software developer, my feeling is that implementing such model instead of the very usual slip curve model could be a win win situation. Possibly richer model at the end, probably less problems adjusting it, more intuitive. Don't see the problems precisely in advance...but usually I am not too bad guessing which general direction is less crowded with problems than the other
Last edited by Juls, .
Yes easier to implement, but then most of time you are not satisfied. IMO models based on slip curves don't set the problem the right way.
IMO this is the correct way to set the problem:
We have a tyre on the road, we push on the axis following a given force vector. What is the vector of the reaction force?
As soon as we set the problem this way, we sart using formulas involving time.
Even the simplest formula using time (model tyre as a set of non linear springs and dampers matching the slip curves) will avoid many pitfalls you get with slip curves. Because for example with slip curves and a discrete time physics engine, it is very easy to get reaction force stronger than the pushing force, tyres sliding magically at very low speed...etc.
All these flaws are already contained in the very beginning, when you decide to start from slip curves.
For me slip curves are tyre benchmark results, a very good way to check afterwards if your model matches real tyre...but not a starting point to write a model. But maybe I am crazy
Last edited by Juls, .
Your first surface looks OK, but second one there is definitely something wrong.
Look what happens. First you corner and it gives nice grip...then you start braking (slip ratio increases) and the grip collapses...but as soon as the tyre slips more longitudinally grip comes back magically, almost at pure cornering level!
That's the whole problem with tyre slip curves. Tyre has many variables and gives reaction forces through a friction/stiction process very nice to model with semi-empirical brush models. These models are very intuitive to implement, they deal with real things, not coefficient for magic formulas. And you can "easily" introduce transients.
The lateral and longitudinal forces vs slip curves are two simple pictures showing only a single aspect of the tyre output. They give no information about hysteresis, transients, influence of other vital parameters...and they are not intuitive at all as soon as they are combined...you can easily get something weird changing one parameter. They are far not enough to model a tyre, and they don't help you when you introduce influence of other parameters.
When you use a brush model or something like that, you think about the shape of the contact patch, the pressure distribution, sticking area and sliding area...this is intuitive and you can immediately guesstimate what camber could change for example... For me it looks a lot easier to scale such model.
Yes I look at the end of slip curves and see at least 20%-30% drop. I know it is for wide slip angle but for me such drop should happen only when tyres are locked and what remains is only rubber dynamic friction...but these friction curves are used all the time by the game even when tyres are rolling and progressively sliding.
For me the key in tyres are transients. For example, when a tyre deforms during very quick actions it can give 1.5 times peak forces for 1/10th of a second....seen something in a study about that somewhere. This is massive stability help during transients! Which sim models that?
Yes in Shift when stopped if you turn the wheel it resists, and when you release it the tyres relax that's pretty well done...there is no such thing in iRacing or it is hidden by the strong dampening they add.
The separate Fx and Fy look far better than before
It has been debated over and over, but there has been a change in literacy concerning the FX curve.
In older books like Milliken Milliken, the Fx curve reaches a peak and then decreases significantly (15%-30%).
But more recently, many tyre measures set show something different: Fx reaches a peak and then almost does not decrease...5% maybe...unless you really lock the tyres or reach crazy slip angle.
In most reasonable sliding situation, the decrease in force you feel in the steering wheel comes from the fact that contact patch shape/position changes. As a result, even if Fx decreases only 5%, the point in which it applies moves closer from the tyre pivot point and the aligning moment you feel in steering wheel decreases because of that (pneumatic trail decreases).
Recent sims (including LFS) have IMO adopted this approach, and Fx is almost flat after the peak. This gives ability to drift (real tyres do it, so tyre model should allow it), and avoids the punishing unrecoverable spin you get as soon as you go above grip limit in older sims (GTR2).
It has been debated over and over, but there has been a change in literacy concerning the FX curve.
In older books like Milliken Milliken, the Fx curve reaches a peak and then decreases significantly (15%-30%).
But more recently, many tyre measures set show something different: Fx reaches a peak and then almost does not decrease...5% maybe...unless you really lock the tyres or reach crazy slip angle.
In most reasonable sliding situation, the decrease in force you feel in the steering wheel comes from the fact that contact patch shape/position changes. As a result, even if Fx decreases only 5%, the point in which it applies moves closer from the tyre pivot point and the aligning moment you feel in steering wheel decreases because of that (pneumatic trail decreases).
Recent sims (including LFS) have IMO adopted this approach, and Fx is almost flat after the peak. This gives ability to drift (real tyres do it, so tyre model should allow it), and avoids the punishing unrecoverable spin you get as soon as you go above grip limit in older sims (GTR2).
Pacejka is great to develop a model faster. But now it is quite old. I mean there are plenty of models using other approach (for example focusing on the tyre contact patch shape and pression repartition) modern computers can crush far enough numbers to use such models.
Parameters for such models are more meaningful than in Pacejka, and they model transients quite well. And from the way they work Fx and Fy are already take each other into account.
Good comprehensive thesis:
http://www.control.lth.se/documents/2007/jsvenPDH.pdf
Parameters for such models are more meaningful than in Pacejka, and they model transients quite well. And from the way they work Fx and Fy are already take each other into account.
Good comprehensive thesis:
http://www.control.lth.se/documents/2007/jsvenPDH.pdf
Is it possible to "sense" a patch approaching? If yes, then since few days I "sense" it.
So if I am right I can start a new career, and if I am wrong nobody will remember anyway.
This curves are....surprising. After 30% longitudinal slip your tyre suddently regain some grip.
So if I am right I can start a new career, and if I am wrong nobody will remember anyway.
This curves are....surprising. After 30% longitudinal slip your tyre suddently regain some grip.
Great to see progress reports! Thank you!
Have you heard about Vuzix head mounted display. Two LCD screens directly in the glasses.
And I suppose it is supported by directx 8 games like NFS without any problem. The driver renders 2 views, one for each eye.
Oops sorry didn't see the post about z800. Z800 looks like better HMD, more expensive too.
And I suppose it is supported by directx 8 games like NFS without any problem. The driver renders 2 views, one for each eye.
Oops sorry didn't see the post about z800. Z800 looks like better HMD, more expensive too.
If it was suitable for dome, then 360 degrees FOV would show everything in all directions. This is not the case.
I mean display is only splitted horizontally in viewports, not vertically. Vertically it is still exactly like before, not suitable for a vertically curved screen. Otherwise there would be other parameters to configure the vertical splitting of view in viewports.
cylindrical perspective shows the same kind of distorsion for flat surfaces going through the entire view...like bridge.
Here 180 degrees cylindrical (not spherical ) perspective:
http://upload.wikimedia.org/wi ... lindrical_perspective.jpg
I mean display is only splitted horizontally in viewports, not vertically. Vertically it is still exactly like before, not suitable for a vertically curved screen. Otherwise there would be other parameters to configure the vertical splitting of view in viewports.
cylindrical perspective shows the same kind of distorsion for flat surfaces going through the entire view...like bridge.
Here 180 degrees cylindrical (not spherical ) perspective:
http://upload.wikimedia.org/wi ... lindrical_perspective.jpg
Last edited by Juls, .
No wonder it did not work. If you set 40 degrees FOV for center monitor and angle 0 for the sides it is just like LFS before patch Z25 with 95 degrees FOV
Try 2 monitors on each side, and 20 degrees center monitor, 20 degrees monitor angle...and you get 100 degrees FOV with the center looking exactly the same as before when you used 80 degrees FOV. 3 monitors on each side with 14 degrees center monitor, 14 degrees side monitors gives smoother result.
To use this with one single monitor, the quickest way, in options/view:
- line multiple screen layout, set a number for left and right screens...for example 3 on each side. Now the game will stitch 7 views to build the final view.
- If your desired FOV is for example 140 degrees, set main screen FOV and screen angle to 140/7=20 degrees. That's it.
Using a 114 degrees FOV with multiple viewports gives the same in center than the default 90 degrees view, but avoids distorsion on the sides. (at least it is not anymore the same distorsion...this one , barrel distorsion, is far less annoying for precision and sense of speed).
3 screens on each side, main screen FOV=screen angle=114/7=16-17 degrees
Try 2 monitors on each side, and 20 degrees center monitor, 20 degrees monitor angle...and you get 100 degrees FOV with the center looking exactly the same as before when you used 80 degrees FOV. 3 monitors on each side with 14 degrees center monitor, 14 degrees side monitors gives smoother result.
To use this with one single monitor, the quickest way, in options/view:
- line multiple screen layout, set a number for left and right screens...for example 3 on each side. Now the game will stitch 7 views to build the final view.
- If your desired FOV is for example 140 degrees, set main screen FOV and screen angle to 140/7=20 degrees. That's it.
Using a 114 degrees FOV with multiple viewports gives the same in center than the default 90 degrees view, but avoids distorsion on the sides. (at least it is not anymore the same distorsion...this one , barrel distorsion, is far less annoying for precision and sense of speed).
3 screens on each side, main screen FOV=screen angle=114/7=16-17 degrees
Last edited by Juls, .
Barely distorted if you use enough viewport. This is a pretty good approximation of perfect cylindrical perspective.
Distorsion for a single viewport showing X degrees horizontal FOV can be estimated:
d=tan(0.5*X)/(0.5*X) -1
This figure is the difference between what the viewport shows and perfect cylindrical perspective.
Default view in LFS shows 90 degrees horizontal FOV. In that case d=27%.
360 degrees view with 11 viewports gives d=2.8%.
180 degrees with 11 viewports d=0.6% at this level you barely see transitions between viewports. All this for a 20% performance drop. Pretty good!
Distorsion for a single viewport showing X degrees horizontal FOV can be estimated:
d=tan(0.5*X)/(0.5*X) -1
This figure is the difference between what the viewport shows and perfect cylindrical perspective.
Default view in LFS shows 90 degrees horizontal FOV. In that case d=27%.
360 degrees view with 11 viewports gives d=2.8%.
180 degrees with 11 viewports d=0.6% at this level you barely see transitions between viewports. All this for a 20% performance drop. Pretty good!
Hi Technique,
Very nice dome!
If you ask LFS to render the view using for example 11 viewports, what you get is exactly what you need for a cylindrical screen (not a dome).
For example, 9 viewports, center screen 30 degrees FOV, all other viewports 30 degrees....it gives you a 270 degrees view.
If you split this view on three projectors using triplehead2go or ATI eyefinity, and project these three views on a 270 degrees cylindrical, 90 degrees for each, it should be ok! (the only problem may be picture blurring)
Even better, if you use only three viewports, 90 degrees for each, you get three views ready to be projected on three flat walls of a room, or for three large screens placed at 90 degrees from each other and surrounding you!
With 4 viewports you can cover 360 degrees with 4 projectors on flat walls or 4 monitors all around you!
Very nice dome!
If you ask LFS to render the view using for example 11 viewports, what you get is exactly what you need for a cylindrical screen (not a dome).
For example, 9 viewports, center screen 30 degrees FOV, all other viewports 30 degrees....it gives you a 270 degrees view.
If you split this view on three projectors using triplehead2go or ATI eyefinity, and project these three views on a 270 degrees cylindrical, 90 degrees for each, it should be ok! (the only problem may be picture blurring)
Even better, if you use only three viewports, 90 degrees for each, you get three views ready to be projected on three flat walls of a room, or for three large screens placed at 90 degrees from each other and surrounding you!
With 4 viewports you can cover 360 degrees with 4 projectors on flat walls or 4 monitors all around you!
Thank you so much Scawen. The possibility to use more viewports than screens gives exactly what I have been waiting for in a racing game!
Cylindrical perspective! Look at these two screenshots (single monitor). This is the exact same view, with the same FOV (130 degrees), one using perspective view like all sims excepted LFS do, the second one with multiple viewports like only LFS can do.
Look how distorted objects are on the first screen sides, how difficult it is to understand where is the apex, how the center of the view looks ridiculously small. Difficult to appreciate speed, distances, orientation, poor spatial awareness.
Second view, even if there is barrel distorsion, keeps aspect ratio almost unchanged and this is what matters in racing. A 90 degrees turn will always look like a 90 degrees turn, from the side to the center of your monitor. Apex is where it visually appears to be all the time. Speed is consistant in all directions, distances and angles too.
Look at the poles on the left side, the track texture...clouds, trees on the right side. And the most important...turn looks different! Closing turn on the first screenshot, not on the second screenshot.
That is why when you try a racing sim for the first time you always turn too strong. Every turn looks like it is closing. And this effect is already present (moderately) with 90 degrees FOV.
Look how horizon is curved on the first screenshot, the tunnel effect, and flat on second screenshot.
Very quickly we forget entirely the barrel effect and this view gives a far better sense of depth and accurate sense of speed. Thank you again it is already Xmas for me !!!
130 degrees FOV on a single tiny monitor without distorsion. Which other sim can do that?
Cylindrical perspective! Look at these two screenshots (single monitor). This is the exact same view, with the same FOV (130 degrees), one using perspective view like all sims excepted LFS do, the second one with multiple viewports like only LFS can do.
Look how distorted objects are on the first screen sides, how difficult it is to understand where is the apex, how the center of the view looks ridiculously small. Difficult to appreciate speed, distances, orientation, poor spatial awareness.
Second view, even if there is barrel distorsion, keeps aspect ratio almost unchanged and this is what matters in racing. A 90 degrees turn will always look like a 90 degrees turn, from the side to the center of your monitor. Apex is where it visually appears to be all the time. Speed is consistant in all directions, distances and angles too.
Look at the poles on the left side, the track texture...clouds, trees on the right side. And the most important...turn looks different! Closing turn on the first screenshot, not on the second screenshot.
That is why when you try a racing sim for the first time you always turn too strong. Every turn looks like it is closing. And this effect is already present (moderately) with 90 degrees FOV.
Look how horizon is curved on the first screenshot, the tunnel effect, and flat on second screenshot.
Very quickly we forget entirely the barrel effect and this view gives a far better sense of depth and accurate sense of speed. Thank you again it is already Xmas for me !!!
130 degrees FOV on a single tiny monitor without distorsion. Which other sim can do that?
Last edited by Juls, .
Great, I enjoy progress reports and communcation!
I suppose after that you get at least 75% less moaning.
I suppose after that you get at least 75% less moaning.
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