Assets NWH Vehicle Physics

Ah, the problem is then likely the fact that I switched from rigidbody constraints to kinematic rigidbody for inactive vehicle and Unity does not do OnCollision callbacks when using default settings. Try going to project settings, physics section and ticking "Enable Kinematic Static Pairs".

 

The problem you are having here can be fixed by enlarging the body object collider (cube) to extend to the wheels. Problem here is that since the rigidbody is so small and all the mass is contained in one relatively small spot inertia is also quite small making reactions to any force quite severe. Think of lever effect. Rigidbodies in Unity in general react quite badly to forces that are applied far out of the volume of the rigidbody colliders. Think of applying force to the object at a point that physically does not exist.

 

Hello, is there a way to use the ground detection script with a mesh (generated from a terrain) instead of a terrain?
I can't use a simple unity terrain in my mobile game since it's too heavy and it kills performances.
I currently have something like this:

If this is not in the scripts already, I think it would be a really cool feature since most game developers targeting iOS/Android are forced not to use the unity terrains...
Thank you

 

Hello, there is no such support at the moment. One way to do it currently would be to split the mesh by splat texture and tag each object accordingly (tags are supported). Of course this might be problematic in case there is a lot of blending happening.
Another way of doing it would be using texture coordinates: https://docs.unity3d.com/ScriptReference/RaycastHit-textureCoord.html
This should be fairly easy to implement but would have to depend on pixel color at point. Modifying ground detection script to return that instead of the terrain texture index would probably be the way to go. If you are not in a terrible hurry I will add this to TODO and ship with the next update. If you are, send me an email.

 

You are too kind, and I'm not in hurry at all...still many months before the release of my game...thank you for the fast reply as always.
I forgot to reply to your answer related to my previous question (about the damage not working properly) so I'll do now.
I made a new unity project and I imported only nwh physics, then I opened the demo scene and I started driving around.
I had also modified the collider of the car I was driving (the Ferrari 458 one), by removing the box colliders and using the provided mesh collider, hoping to get better accuracy.
To test the damage I started hitting the wall of the small house included in the demo scene at different speeds.
I got a deformation at first, but not with the physics setting you suggested ("Enable Kinematic Kinematic Pairs") but with "Enable All Contact Pairs".
The problem is that after this first, good, damage I was not able to damage the car any further. Even after fixing it by calling the fix function I could not get more damages. I thought this issue was related to the max damage setting but I don't think it's related to that since even after setting it to a very high value nothing changed.
At this point I really don't know if it's something related to my physics settings (which by the way should be pretty standard since I tested this in a new project), my car settings (but again, even when using the default values it doesn't work) or if there is something wrong in the code itself.
Again, no need to rush this...if you could check this out when you have time though that would be great

 

Check #601 up above, I mentioned the fix there. I have yet to test it but it is almost certainly the reason for the problem since the collision code has not been touched for a few months and the sleep system and optimization has.

 

Hello,

I have an issue with the cars jittering at very slow speed (barely moving speed). Spring force and center of gravity are ok. From what I've seen it is related it the Side (lateral) Force Coefficient of the Wheel Controllers. To replicate this play Island scene with the Sedan and increase the Side Force Coefficient (1.6 or 1.8 for example, the higher you go the more violent the car shakes near to standing still speed, but once you get to speed everything is smooth).
My cars are set up with longitudinal and lateral slip/force coefficients of 0.7/1.2 front and 1.2/1.6 rear (understeer bias) and they handle great in the corners at normal or high speed, they have exactly the level of grip I was looking for, but the drawback is that I have this jittering when barely moving which causes tyre screech and also shakes the camera.
Is there a (nice) solution or workaround for this ?

Thanks

 

Hello,

in the demo szene (manual transmission), although i got the box "automatic clutch" unchecked i am able to go freely through the gears without pressing the actual clutch. In addition the engine should be stalled if breaking to hard without hitting the clutch and it shouldn`t be possible to start in 6th gear. Is this a bad on my part with the settings, or is this behaviour just not implementet yet?

Thank you!

 

Not 100% sure, but try to play a bit with the fixed timestep (Edit->Project settings->Time->Fixed Timestep) and check if when you decrease it it gets getter

 

Out of the question, I'm targeting a large range of mobile devices (up to 6 years old) so further reducing the fixedtimestamp is not a viable option, it comes with a high CPU impact, 0.015 is extremely low as it is.
Hacks can be done, nonetheless, I can adjust the coefficients based on the speed of the car so it will grip better the faster it goes, but this implies further checks on every update (or even worse on every fixedupdate) and I'd like to avoid that as well.

 

Hello there and sorry for taking some time to answer, went away for the weekend.
If anyhow possible I would recommend against upping the force coefficients too much on the wheels. The reason for the problem is that coefficient of 1 would give you about realistic grip and 1.6 would be 1.6 times that. Time passed between two physics updates is quite large (compared to real world where it is essentially 0 if you look at it in that way) and so if the calculation is too tight a kind of feedback loop gets introduced which results in jitter. It tries to compensate for error but it overcompensates and insteads moves the wheel the other way instead of just stopping it. This is precisely the reason we can not have really fixed physics joints in games. Now, there are two ways to improve this: reduce time between updates as you increase the coefficient (Time.fixedDeltaTime should be roughly 0.02/coefficient from my experience) or reduce the force coefficient - or find the compromise between the two. If you need more stability in corners and less slip you can play with stability drive assist which is not physically accurate and does not work on slip-based calculations so you can up it quite a lot. Hopefully this helps and puts some light on things.

 

It for sure would be a hack but since WheelController3D has quite a stable API you could do an external script that sets the side slip coefficient to some lerped value depending on speed:

float sideSlipCoefficient = Mathf.Lerp(1f, 1.6f, vc.ForwardVelocity * 0.25f);

I know it is a hack but should work fairly well. The example above lerps between slip of 1 and 1.6 from 0m/s to 4m/s.

 

Yeah, most likely I will go this way, just wanted your thoughts on it as well. Thanks

 

I've cracked it, not perfect, but it reduced the jittering by so much I could leave force coefficients to 1.4 and also double the FixedTimestamp to 0.03 which made a HUGE difference in the game performance. The overall handling I'd say it is ~90% sharp as before, so it won't be noticed in most games.

It tries to compensate for error but it overcompensates and insteads moves the wheel the other way instead of just stopping it.
This was of great help for debugging it. This corner case meant that at each iteration/computation the forces would have different signs (positive / negative), and they would be quite big in value and almost equal in absolute value. This effect can be resolved by keeping the previous computed force and always assign the mean between the previous and the current one. The minor downside is that it automatically lerps the force when it is constantly in a direction. For example instead of putting down an instant force of 5000 it will put 2500, followed by 3750, 4375, 4687 ... But it happens very fast, so it gets to >90% of the original force in 5 iterations, that is 0.15 of a second.

Below is the updated code from WheelController.FrictionUpdate() :

sFriction.force = (prevSForce + (Mathf.Sign(sFriction.slip) * activeFrictionPreset.Curve.Evaluate(Mathf.Abs(sFriction.slip)) * wheel.tireLoad * sFriction.forceCoefficient * 1.3f)) / 2;
prevSForce = sFriction.force;

Hope this helps others targeting low end devices (observation : fixedframerate is autocorrected by VehicleController.Start() method to a max of 0.015, so you'd need to comment out that part as well to get it higher).

Cheers,
Jbs

 

I have actually done this and even tried doing moving average over multiple frames but beware that you might get the infamous drifting on a sloped surface when standing still effect. Of course with the newer versions of NVP it is not such a problem since it disables the vehicle when it detects it is still and makes it kinematic both to save on performance and prevent creep, but this is the reason I removed the smoothing and went for accurate instead. There is always a downside. Interpolation, extrapolation, whatnot there is always so corner case. Anyways, glad you got it there - I am thinking of doing some kind of slider to adjust this.

 

Yes, the sliding slope test at standstill or near-standstill speed was the first I tried after the change but it held the car very well. And like you pointed, every change has pros and cons, and is about finding the best compromise for your scenario.

I am thinking of doing some kind of slider to adjust this
That would be cool

 

Hello @NWHCoding , I am trying to change the suspensions' height of my vehicle at runtime using a slider.
The slider goes from 0 to 0.1f, and I made a function to set the y coord of the WheelController's transform component whenever the slider value changes.
The problem is that it doesn't work...well it does something, but it's crazy: the transform component is set to weird values, and even the x and z coords are affected (when they should not be, according to my script below).
I believe it's something related to other NWH scripts conflicting with it.
Here is the code I used:

Code (CSharp):

1.  public void UpdateSuspensionsHeight(float newY)
2.     {
3.         Vector3 pos = wheelControllers.transform.position;
4.         pos.y = newY;
5.         wheelControllers.transform.position = pos;
6.     }

Do you have any clue about it? Am I using a wrong approach? Thanks

 

If your goal is to raise/lower suspension while keeping the same spring length your approach is valid BUT you have a big gleaming error in there. You are settings transform.position on a child object which means that if your car is at 200 meters above origin and you set the Y of one of it's children, that child will end up 200 meters below the car.
What you need to do instead is:

Code (CSharp):

1. void Awake()
2. {
3.      initialPosition = wheelController.transform.localPosition.y
4. }
5.  
6. void SetHeight(float offset)
7. {
8.      wheelController.transform.localPosition.y = initialPosition + offset;
9. }
10.  

Or alternatively you could just increase the spring length - depends on what your goal is.

 

Thank you, worked like a charm

 

Hi. Should there be a Backfire component in the Vehicle Controller? I see references to various Backfire scripts but I don't see any input fields in Vehicle Controller. Cheers.

 

I am pretty sure it is under Effects as it is pretty much only a visual effect.

 

Hello @NWHCoding , today I am here again to suggest you a feature that in my opinion would be really cool and useful.
So one of the biggest issues when an asset is open source (which I actually appreciate) is that to add custom features you are usually forced to edit the asset's code itself (or write a wrapper around it that most of the times is overcomplicated and performances-expensive); but then every time an update comes you lose time trying to reapply your changes.
How could this be mitigated? Let me explain by a few examples.
1) I wanted to show a short message whenever the vehicle that the player was driving got flipped over. To do this i had to add a few lines of code near the flip over script. Easy, but not maintenable on the long term.
2) I wanted to show a message whenever the player's vehicle started drifting (and count the drift time when it finished to reward the player with some coins). A bit less easy than the previous example but still nothing hard, yet again it will be broken by the next NWH update (which will be very welcomed in any case ).

My advice is adding some "InteractionEvents" to fit our most common needs. A new tab could be made in the vehicle controller script (Maybe called "Events"?) containing all the events that could be triggered while playing. This would provide a ui button-like GUI where we could pass our scripts' functions to it. To make this even more useful, dynamic parameters could be passed (https://forum.unity.com/threads/invoking-unityevent-with-argument.282670/).
So, for example, the hypotetic OnDriftStart() event could pass the start time to my method...or even better, it could pass a custom struct containing all the drift info (start time, start coords and so on).
Another event that I can think of could be "OnGearChange" to update my digital gear display only when I actually need to update it instead than having to write it every time in an Update() loop (Although there may be already a built-in method that works better for this but i have not checked yet).

Anyway, every time I wrote here in the past asking about ways to do something, you always added what I needed to the to-do list.
By writing this post I am really not trying to force you to add this feature, but I would love to hear your opinion about it since I really believe it could improve the flexibility of this great asset.

Thanks for reading !

EDIT: Adding a screenshow below about what I explained before just to make it more clear and easier to understand, especially for other NWH customers.

Maybe the readers of this thread could tell us if they would find it useful or not as well

 

I have a racing game in progress,after several days working on the integration of this driving system, it looks good until when i run the game in the real environment which is many NPC cars driving together, I found that the FPS dropped into a unacceptable number, I looked into the code, found that the fixed time step is set to 0.015, that is obviously quite a burden. 0.05 is the number i d been using considering my game is pretty heavy on physics. now, i do not have any idea to solve this problem.

note, only the current player is using this system, other cars are still implementated with unity wheel colliders. is there anyway that i can still use a high fixed time step that NVP can live with???

 

Hi,
Can you please AsmDef files to the asset to improve compilation time? Many assets are AsmDef friendly these days and this asset should be also.

This will require reorganizing folder structures by putting all editor related scripts into the single Editor folder.
Thanks.

 

Just posted the same question in the Edy's Vehicle Physics thread. I don't own NWH yet, so I'm not super familiar with it.

Would it be possible with NWH Vehicle Physics to set up a weird suspension that would work in this sci-fi vehicle (from the asset store):


That asset comes with a simple physics setup with a suspension that just moves the wheels with terrain. The elaborately modeled suspension pieces are then static. Ideally the lower pieces that attach to two wheels each would rotate and the big upper suspension bar things would react at least somewhat to terrain.

If that's not a good fit for NWH, is there another asset that is more geared toward that sort of thing?

 

Mirror - Community replacement for UNet (https://github.com/vis2k/Mirror)

+1 for that should have at the top of the poll really, really good plugins for it aswel like litenetlib for udp support.

And for the next poll.. a motorbike controller

 

Hey @NWHCoding
How can you limit the speed of the car without changing the parameters of the engine and transmission?

 

Hello again,

I think I may have found a bug. The motor makes the wheels spin when the car is upside down even in neutral. When in a gear other than neutral and the car is upside down, RPM hangs where it's at and won't decrease.

(Thanks in advance if you end up looking into this.)

@Kvazimado Try General -> Speed Limit? It's in meters per second, not kilometers per hour, in case that's an issue.

 

Hi, I have added " * wheel.brakeCoefficient" on line 152 and 164 in brakes.cs, because I was not able to separate overall brake force and handbrake force.
Now if I set max brake torque to 40000, axles brake coeff. 0.1 and handbrake coeff. 1.0 the car behavior looks correct when braking/handbraking.
Also decreasing side friction force coeff. for wheels was necessary.
If there is other solution or there was some other intention why was wheel.brakeCoefficient missing on those lines, let me know.

 

I'm considering buying but I have a couple of questions:
1) Can I use the physic calculations of the plugin without using physics? What I am trying to do is have the dial
up and running and connect it to the speed of a model and the rotation of the wheels without having colliders
and other physics calculations which could potentially be heavy for mobile.
2) Does your plugin support motorbikes? I've only seen vehicles with more than 2 wheels so I wondered if you support
less.

 

+1 would agree , more modular and easier to extend without needing to making big changes to the original source to add in hook in events.

Also @NWHCoding some things are a little broken in 2019.1f1, the car prefabs have problem when clicked on from project window and shown in the inspector like something is changing them constantly causing lag, icon changes, mouse cursor pointer>timewait etc

Would be nice to see the new unity 2019 input manager support for the vehicle controller, so a defined vehicle controller inputmap.

Also wish you had supported mirror first not photon, its open source and has some really good third party assets for it that I'd rather use like https://vis2k.github.io/Mirror/Transports/Multiplexer.html and https://vis2k.github.io/Mirror/Transports/LiteNetLib4Mirror

 

Thanks for the +1, I really believe we all need something like that.
About that 2019 prefabs window, I thought I was the only one with that issue...well, apparently not.
A fix is required for sure since it's really annoying ^^

 

I actually first saw a similar prefab issue with another addon I'm testing for emotitron(mirror plugin dev) and he has a prefab example that was doing a similar thing in 2019.1 ..commenting out the below code fixed it, so not sure what is in the prefabs nwh-vehicle but I'd imagine maybe something similar

 

Hi again...well after wasting so much time every single time I wanted to edit a prefab containing a vehicleController script I decided to debug that issue (And I should have done it much earlier).

FIX BELOW:
Open the VehicleControllerInspector.cs script, then go to line 74:

Code (CSharp):

1. EditorUtility.SetDirty(vehicleController);

This is forcing unity to save the whole script variables over and over again, since it's called in OnInspectorGUI().
To fix that, just add an if check to save those values only when we actually change some of them:

Code (CSharp):

1. if (GUI.changed)
2. {
3.     EditorUtility.SetDirty(vehicleController);
4. }

Disclaimer: I have never coded a unity asset nor used these kind of functions, and this fix comes from a 5-minutes google search, but as far as I know it works fine and there are no downsides. Enjoy

 

nice man, where is @NWHCoding anyway?

 

I saw him replying on some threads related to other assets he is working on, I guess he is focused on those one atm...

 

@GearheadLydia thx.
Maybe you know and about that - As in the speed limit to make the transmission used all of the transmission without changing the engine power and rpm?
@NWHCoding

 

Hello! When I download an asset, it shows me that this is version 1.7.4, and not 1.9.2. Am I doing something wrong?

 

Hi, I am encountering this problem too. Has this been answered?

 

Hey, i just recently bought your asset. Im making an offroad game and i got issue that when i try to reach steep hill, i cant reach the top because car engine always lock down. I've even increased final gear ratio to simulate low range... What can i do now?

EDIT: So far i have several issues. Suspension physics are awesome, i must say that these curve settings are perfect. Only thing which confuses me is that the car gets damaged only once after impact. I've read through this forum and saw that something in physics needs to be set. I did that and unfortunately, nothing changed. Another issue i recognized is that when car passes from road to terrain, in some scenarios i can still hear skid sound looping. I would love some help, thanks for any response.

 

I also noticed several times when I press handbrake and my car is sliding from one ground type to another(where the car stops), skid sound start looping.

EDIT: Probably some code inspection is needed and find place where the handbrake code and audio code is handled and check why it does not stops all car audio emiters when physics calculations are stopped.

 

Update 1.9.3 is on the way with the following changes:

• Added vehicle auto-setup script.
• Major improvements to collision detection.
• Added vehicle collision event.
• Added sub-material index option to vehicle lights.
• Added per-gear throttle limiting to make low geared, high power vehicles easier to drive using binary input.
• Added adjustable auto brake velocity on reverse direction.
  
• Fix GC on WC3D.

Expect it tomorrow (it has been submitted but is waiting for approval).

This should solve the problems with collisions and hill-climbing.

 

Upcoming update (1.9.3, expected tomorrow) will add event for collisions. This is a great idea and more events will follow. Sorry for not replying earlier, I visit the forums twice a day and no notification ever popped out despite the thread being set to watched.

 

Hello,
you can use default fixed time step, it is just that it is not recommended. Most racing games run at even higher step (100Hz/0.01ms) but those are desktop games and usually quite CPU intensive.
Are you sure you are running version 1.9 or newer (Unity 2018.3+ required) and profiling the build?

 

PSA: It seems that this forum has problems with Watch Thread option. There have been 0 notifications in any form about any posts in this thread and therefore I completely missed all the posts from last TWO months. Really sorry about that and will have to find some 3rd party plugin to monitor the thread. I have been very active in all other threads and replying to all the messages on the same day, it is just this one that did send any notification.
This is my forum feed - anyone see this thread anywhere? Exactly.

 

Hello and sorry for not replying earlier - please check post #645 in this thread.
Yes, NVP would work fine with such vehicle, with two caveats; wheels can not work with 0 suspension travel (about 0.2 is minimum recommended) and collision detection works only for the bottom half of the wheel. So if you can work over those two it would be a good fit.

 

Hello and sorry for not replying earlier - please check post #645 in this thread.
There is a speed limiter under "General" foldout.

 

Hello and sorry for not replying earlier - please check post #645 in this thread.
Unfortunately the answer is no to both. 1st is a no because a Rigidbody is used as a backbone of the physics and there is no way to feed inputs and get outputs in the way you would need. 2nd is also a no and the reason here is that the motorcycles are very different to cars and and a lot of code would need to be modified / removed / added to get it working properly.

 

Nope, check post #645 in this thread. Really sorry about that and while I was working on update for DWP I for sure did not go away, or plan to.

 

Have you tried setting the speed limiter under "General" foldout?
Also, sorry for not replying earlier. Please check post #645 in this thread for the reason.