Until now I think no racing sim simulates this in a proper way.
Direction column friction/damper/spring has two parts: the friction/damper/spring from mechanism (rack and pinion, assisted direction) and the friction/damper/spring from tyres on the road when you steer.
ISI engine tries to simulate mechanism f/d using arbitrary coefficients. If properly adjusted for the FFB wheel, it feels nice.
Tyres friction/damper/spring from tyres while steering depend on front load and wheels rotation speed. As you go faster, it quickly becomes very small compared to steering forces. I suppose that is why sims do not simulate it.
I think FFB in racing sims is still in it's infancy. Every racing sim should come with a tool to help you choose the proper FFB strength, damper, friction, so that your wheel left alone behaves as sim developer want in some specific condition. Wheels are very different in inertia, power, reductor...but this can be estimated automatically with a tool performing a benchmark. With such a tool, a sim could feel almost the same on various wheels.
Edit: rFactor RealFeel plugin seems to simulates this thanks to LBodnar LeoFFB plugin. Above a certain speed, it uses steering forces for FFB. Below it uses friction calculated from load, speed, rubber stiffness...
Last edited by Juls, .
For dual screens: http://www.lfsforum.net/showthread.php?t=31026
There are two versions in the thread if necessary.
Great expaination, I read it before. I just wanted to make a very very simplified explaination. With mechanical trail, pneumatic trail, and even tyre torsion... finally, steering wheel force feedback remains quite similar to a stiction/friction.
The FFB drop above grip limit is certainly not 90% or 100% like in ISI engine. As I read some time before here, nothing magical happens when the tyre starts sliding, changing rubber into wet soap. Rubber is still resisting as much as it can and trails do not vanish...
The self-aligning torque curve one can find everywhere is misleading, because many people took it for the overall steering wheel FFB.
From my own (limited but carefuly observed) experience, when you turn more and more, the wheel resists strongly, and the resistance increase as you turn until you reach the grip limit. You have to push stronger and stronger to turn the wheel. There is a direct relation between the wheel angle and the force you have to apply. It helps our body to have a very precise control of the wheel.
Then, when you overcome the grip limit, the wheel resistance does not drop suddenly, the most important thing is that it ceases to increase with angle. Because of that, the wheel feels lighter to turn, but it is not. It feels loose because there is no more relation between the wheel angle and the force you have to apply as before...
I think from the FFB point of view, when you overcome the grip limit it is very similar to what you feel when you push a heavy object on a concrete floor:
http://www.lightandmatter.com/ ... 5/figs/friction-graph.png
Resistance does not drop suddenly, but become "flat" as the object starts sliding.
Then, when you overcome the grip limit, the wheel resistance does not drop suddenly, the most important thing is that it ceases to increase with angle. Because of that, the wheel feels lighter to turn, but it is not. It feels loose because there is no more relation between the wheel angle and the force you have to apply as before...
I think from the FFB point of view, when you overcome the grip limit it is very similar to what you feel when you push a heavy object on a concrete floor:
http://www.lightandmatter.com/ ... 5/figs/friction-graph.png
Resistance does not drop suddenly, but become "flat" as the object starts sliding.
In these two pictures, the car has a very realistic shadow, very dark, and does not "float" like usually. There is even a reflection on the road which has the color of the car. Amazing.
Is it an edited screenshot, or coming from this addon??
Yes, this is the best improvement in immersion I have seen since years. It has to be implemented !
In the second view you turned the camera? I was doing like that and it causes some distorsion in the cockpit.
There is a possibility to translate the view left or right without any special distorsion:
http://www.lfsforum.net/showthread.php?t=31026
There is a possibility to translate the view left or right without any special distorsion:
http://www.lfsforum.net/showthread.php?t=31026
Shadows
I searched, and I hope this subject was not treated before. Shadows are critical to obtain nice, believable graphics.
Look at this scene, with a car in a sunny environment:
The car shadow has two different areas:
- A light shadow area, the shadow caused by the car volume projected on the road. This area does not receive anymore the direct sun light, but still receives indirect light bouncing on surrounding objects. That is why it is not completely dark. LFS supports that type of shadow.
- A very dark shadow area directly under the car. This area does not receive direct sun light nor indirect light. We are used to see such very dark area under every object close from the ground, and when it is missing, we have difficulties to know whether an object is really in contact with the ground. LFS does not support that kind of shadow, unfortunately.
I think it would be nice to have that type of shadow too, because it improves a lot graphics, and it is present all the time, not only in sunny condition:
A quick and dirty edit to show what looks like this real picture without this shadow...car is floating! :
http://img182.imageshack.us/my.php?image=noshadowzy3.jpg
You can add all possible fancy effects, there is no way to do something looking realistic without this shadow. And I suppose it can be done almost the same way projected shadows are done currently.
Look at this scene, with a car in a sunny environment:
The car shadow has two different areas:
- A light shadow area, the shadow caused by the car volume projected on the road. This area does not receive anymore the direct sun light, but still receives indirect light bouncing on surrounding objects. That is why it is not completely dark. LFS supports that type of shadow.
- A very dark shadow area directly under the car. This area does not receive direct sun light nor indirect light. We are used to see such very dark area under every object close from the ground, and when it is missing, we have difficulties to know whether an object is really in contact with the ground. LFS does not support that kind of shadow, unfortunately.
I think it would be nice to have that type of shadow too, because it improves a lot graphics, and it is present all the time, not only in sunny condition:
A quick and dirty edit to show what looks like this real picture without this shadow...car is floating! :
http://img182.imageshack.us/my.php?image=noshadowzy3.jpg
You can add all possible fancy effects, there is no way to do something looking realistic without this shadow. And I suppose it can be done almost the same way projected shadows are done currently.
Last edited by Juls, .
Arbitrary distorsion based on a grid one can stretch.
This software seems to do that kind of thing:
http://www.youtube.com/watch?v=7wkp9GhUp58
It could be some very interesting tool...because it is very flexible and matches many users needs at once:
- bend parts of the picture if you use multi-monitors with side monitors turned....two or three or more monitors.
- bend parts of the picture to have multi-projectors views stitching perfectly.
- bend picture if projected on a curved screen or from an unusual projector position.
- add a spherical/cylindrical/lens distorsion to enhance
FOV/sense of speed.
- move the center of the view left or right for people using two or 4 monitors.
The best way to avoid precision loss in the center is to make the game use a higher resolution than screen. SoulHunta wrote a tool for dual-monitor users working that way. When you run this tool, LFS has a new resolution, bigger, in screen menu. And when you move the mouse, the soft switches to normal to avoid menu problems.
http://www.lfsforum.net/showthread.php?t=31026
This software seems to do that kind of thing:
http://www.youtube.com/watch?v=7wkp9GhUp58
It could be some very interesting tool...because it is very flexible and matches many users needs at once:
- bend parts of the picture if you use multi-monitors with side monitors turned....two or three or more monitors.
- bend parts of the picture to have multi-projectors views stitching perfectly.
- bend picture if projected on a curved screen or from an unusual projector position.
- add a spherical/cylindrical/lens distorsion to enhance
FOV/sense of speed.
- move the center of the view left or right for people using two or 4 monitors.
The best way to avoid precision loss in the center is to make the game use a higher resolution than screen. SoulHunta wrote a tool for dual-monitor users working that way. When you run this tool, LFS has a new resolution, bigger, in screen menu. And when you move the mouse, the soft switches to normal to avoid menu problems.
http://www.lfsforum.net/showthread.php?t=31026
This is the idea of this thread. Look at first posts and the pictures...large FOV screenshots with spherical or cylindrical or lens distorsion. I wanted to use simple examples with cylindrical.. but many different mappings could be used for different games.
Nice to see you did something like that, Kegetys. It would be great to have a directx hook adding custom post-processing distorsion to any game. I was thinking about something like that:
- to obtain distorsion, the hook maps the game buffer on a regular grid,for example 20x20 cells. Grid vertices are regularly spaced,but the texture coordinates of these vertices are not regular->distorsion.
- the texture coordinates of the cells vertices come from a text file...allowing all possible custom distorsion...for one screen, for three,for multi-projectors stitching, curved screens....etc. Can be calculated directly from a spreadsheet.
I suppose the tool people use to distort image to project on curved screens works a bit like that. (there was a link few posts ago).
OMG, I can't see anymore ! And I can't play piano, I can't sing... my life is over.
:bigeyes2:
:bigeyes2:
There should be possibility to vote for :"I never come on LFS forums".
These are the most difficult votes to catch.
These are the most difficult votes to catch.
With just one graphic adapter with two outputs, and XP it works really nice with two monitors. Many users decided to uninstall vista and come back to XP.
It seems the problem is caused by the DRM inside Vista. This stupid digital rights management, obsolete thing caused such a deep change in architecture that several important features were removed and overall gaming performance is reduced. (Vista DRM layer checks many things 30 times per second).
I do not have vista but I read somewhere horizontal span mode is no more supported-> impossible to make games believe you have one large display when in fact you have two.
Two screens gaming is no more possible with Vista unless you get a matrox DualHead2Go....for me this is a MAJOR regression. No idea why they did that...this is stupid.
So I suppose this does not come from the mod, but from windows and/or LFS setup.
Did you chose horizontal span in windows (not dual screen)? From your screenshot I would say no, because windows task bar stretches on both screens in horizontal span (unless you use a tool to force task bar on one screen only).
Do you have Vista or XP? With Vista you can NOT extend display on two screens.
Did you chose a large resolution in LFS screen menu?
Is LFS running on two screens without the mod? It should,this mod is only for view de-centering. LFS works on two monitors if horizontal span (not dual view) is enabled in windows and you chose a correct resolution in LFS screen menu.
Hope it helps
Did you chose horizontal span in windows (not dual screen)? From your screenshot I would say no, because windows task bar stretches on both screens in horizontal span (unless you use a tool to force task bar on one screen only).
Do you have Vista or XP? With Vista you can NOT extend display on two screens.
Did you chose a large resolution in LFS screen menu?
Is LFS running on two screens without the mod? It should,this mod is only for view de-centering. LFS works on two monitors if horizontal span (not dual view) is enabled in windows and you chose a correct resolution in LFS screen menu.
Hope it helps
Last edited by Juls, .
If you do not see it, increase the FOV per screen. With 3 monitors using 45 degrees FOV sure it is almost not visible. But if I remember well you were talking about 3 90 degrees views projected on the walls of a room.
When you have three viewports, this is like 3 cameras, one per screen do you agree? With a 90 degrees FOV camera, objects are perfect in the center, and stretch when they reach the side of the screen, don't they?
So with three viewports using 90 degrees FOV, you have three times this distorsion...next car is perfect in the center of middle screen, then it stretches as it goes from middle to right screen, and shrinks as it reaches right screen center.
Try to take two 90 degrees FOV screenshots in LFS and project them on two walls of a room. If you look at the edge between these walls, you will see what I mean.
When I say lines are broken, I do not want to say they are not continuous anymore. They are continuous, but they change angle from one screen to the next one like a line going inside a glass of water. It becomes very visible as soon as you have more than 50-60 degrees per FOV.
3x45 degrees is a good solution for three monitors. It works nice, distorsion is almost not visible. But distorsion exists.
Last edited by Juls, .
You have a black screen with it too? When? When you start the game? There is no resolution to change with this version, and no new resolution appears in the screen menu.
If LFS is able to start, then it is activated.
If LFS is able to start, then it is activated.
Did you notice that this thread has nothing to do with screen size, projectors, and multiple monitors.
In fact it has something to do with it but this is not the main point.
It is about distorsion caused by linear perspective used in 3D libraries like OpenGL and DirectX, and a rather simple trick to correct most of this distorsion.
In 3D games, if you consider an object just in front of you and translate it to the right, it will remain the same size....even if it goes 5 kilometers to the right (assuming you can still see it with 180 degrees FOV). Because only front/rear distance to the object is considered, not lateral distance.
IRL, the same object will look smaller and smaller as it moves to the right. As it should be.
Even if you take three viewports and stitch them together for a three projectors surround setup, you have to do something with that stupid distorsion to have smooth transitions between the three viewports. Of course it is less visible than with a single large viewport, but the three pictures do not match (lines are broken). No way to escape, something has to be done about it, in post or pre-processing, whatever you have: single projector with large FOV,multiple projectors, multiple viewports...etc.
In fact it has something to do with it but this is not the main point.
It is about distorsion caused by linear perspective used in 3D libraries like OpenGL and DirectX, and a rather simple trick to correct most of this distorsion.
In 3D games, if you consider an object just in front of you and translate it to the right, it will remain the same size....even if it goes 5 kilometers to the right (assuming you can still see it with 180 degrees FOV). Because only front/rear distance to the object is considered, not lateral distance.
IRL, the same object will look smaller and smaller as it moves to the right. As it should be.
Even if you take three viewports and stitch them together for a three projectors surround setup, you have to do something with that stupid distorsion to have smooth transitions between the three viewports. Of course it is less visible than with a single large viewport, but the three pictures do not match (lines are broken). No way to escape, something has to be done about it, in post or pre-processing, whatever you have: single projector with large FOV,multiple projectors, multiple viewports...etc.
Last edited by Juls, .
You can try the stupid simple version in my previous post. It should work with any resolution.
Thank you very much for explaining a lot better than me
In fact it would not cause much problem if you look away from the center of the screen....it would even cause less problems than current view.
Look at the current view we have in 3D games. This is a distorted, approximation of a real perspective, where circles become stretched ellipses as they go away from center!
The spherical or elliptical distorsion proposed here is in fact an un-distorsion. Because if you apply it, circles remain (almost) circles even on the display sides. It replaces the odd stretching caused by the linear perspective used in 3D games with a more natural distorsion (barrel) we are used to see in everyday life on TV, pictures.
The instructions the CPU has to perform are specified as a binary code.
Instructions that deal with ints are different from instructions dealing with floats.
So the CPU does not have to recognize what data is. It just execute instructions "stupidly". You can for example store an int in memory, and ask the CPU to perform a float multiply using this int...of course the result will be a total mess as the CPU tries to read the int as a float, but it will run.
This is at CPU level. When you program using a "typed" development language, you have to specify what type a variable is, but you do that to tell the compiler what CPU instructions it should generate at compilation time.
So when you multiply two variables in your code, compiler will generate different instructions for the CPU depending on variable types.
Instructions that deal with ints are different from instructions dealing with floats.
So the CPU does not have to recognize what data is. It just execute instructions "stupidly". You can for example store an int in memory, and ask the CPU to perform a float multiply using this int...of course the result will be a total mess as the CPU tries to read the int as a float, but it will run.
This is at CPU level. When you program using a "typed" development language, you have to specify what type a variable is, but you do that to tell the compiler what CPU instructions it should generate at compilation time.
So when you multiply two variables in your code, compiler will generate different instructions for the CPU depending on variable types.
Last edited by Juls, .
Thank you for the code. I tried to implement the little idea above, and it works (In post above I did a mistake, X and Y to change are one raw upper). So I just override the method SetTransform and the perspective center is translated left or right on the screen. No need for another resolution->framerate is unchanged.
So for example in d3d8.cfg you put -0.50, and in game the perspective is centered on the left screen. +0.5 and you have it on the right screen...and you can use anything from -1 to 1 for adjustment. For people using 4 screens, -0.25/+0.25
Limitations:
*It moves all 3d objects, not 2D->in garage the car translates, not the GUI....but in fact this is good because all GUI buttons remain on screen.
*It reduces the FOV (to avoid clipping on side) and you have to adjust it once in game to correct.
So if you are interested....here is the simple version for LFS on dual screen:
So for example in d3d8.cfg you put -0.50, and in game the perspective is centered on the left screen. +0.5 and you have it on the right screen...and you can use anything from -1 to 1 for adjustment. For people using 4 screens, -0.25/+0.25
Limitations:
*It moves all 3d objects, not 2D->in garage the car translates, not the GUI....but in fact this is good because all GUI buttons remain on screen.
*It reduces the FOV (to avoid clipping on side) and you have to adjust it once in game to correct.
So if you are interested....here is the simple version for LFS on dual screen:
Last edited by Juls, .
It can not work...your center view is real-time, refreshed 60 times per second for example, but your side views are interpolated using the last two or three positions given by server.
That is why for example when you spectate and there is connection lag, the car you spectate seems to crash, and then jumps back to the road...because LFS misses data and interpolates until the car crash, and then receives an update with new car position.
As soon as car movements are not smooth, side views will start to lag badly and turn by steps.
That is why for example when you spectate and there is connection lag, the car you spectate seems to crash, and then jumps back to the road...because LFS misses data and interpolates until the car crash, and then receives an update with new car position.
As soon as car movements are not smooth, side views will start to lag badly and turn by steps.
Yes, we discussed about it in this thread. The main problem is network lag.
Your side views will lag compared to the center view, because they go through the server before coming back, and they are not built from real-time information, but interpolated.
I suppose if you turn with this system, left and right views continue straight a few tens of second, and later turn by steps...and it get worse on server with bad ping. Because of that they are almost not-usable.
This is not a solution. The multi-viewport client has to connect to LFS client for playing smoothly.
Your side views will lag compared to the center view, because they go through the server before coming back, and they are not built from real-time information, but interpolated.
I suppose if you turn with this system, left and right views continue straight a few tens of second, and later turn by steps...and it get worse on server with bad ping. Because of that they are almost not-usable.
This is not a solution. The multi-viewport client has to connect to LFS client for playing smoothly.
But steering mechanism do introduce friction, damper and inertia. It can be calculated from mechanism mass, reduction ratio, geometry, tyre, and assisted steering for some cars.
Sooner or later, a racing simulator should simulate this to some extent. I mean simulated, not introduce artificial effects. Steering column is currently not simulated at all in sims...this is a bit weird as it has a huge impact on how the steering feels between different cars.
Sooner or later, a racing simulator should simulate this to some extent. I mean simulated, not introduce artificial effects. Steering column is currently not simulated at all in sims...this is a bit weird as it has a huge impact on how the steering feels between different cars.
FGED GREDG RDFGDR GSFDG