Vehicles in 3.0?

[pHySiQuE]

Hi, I was just wondering what the status of the multi-body vehicles in 3.0 was. I am planning to start working with this again this summer.

If vehicles aren't implemented, is there any easy way for me to implement a spring slider joint? I think I could use that with the motorized hinge for steering.

[Julio Jerez]

I have a working version now, and If I may say, I believe this is by far the most advanced and realistic vehicle simulation of any real time physics engine

I have two model, one a high performance Lamborghini super car, and the other a Military transport, late I will add a formula one race car.
The parameters for the engine, gear box are taken form the datasheet tables I found on the internet so they are in the ball park realistic.
other parameter I made up.

The cool thing is that all behavior that are characteristics of vehicles, emerge from the simulation, no fakes of any kind, the Vehicle power slide, drift, tail spin, and do all the things real sport cars do.
I am very happy with how is turning out.
I still have some teaks here and there, but for the most part is all functional, check it out.

[pHySiQuE]

Unfortunately I can't use the GitHub visual tool. Why did you change from SVN? Git is so damn confusing.

[JoeJ]

i still ust the svn client as before but with another link:

svn checkout https://github.com/MADEAPPS/newton-dynamics/trunk/ c:\dev\newton-dynamics

But let me know if there is a way without svn client, i'm olso confused by github

[pHySiQuE]

Does that access the same repository and give us the exact same files? TortoiseSVN is pretty easy to use. (On Mac I use Cornerstone, and on Linux I use SmartSVN.)

[Julio Jerez]

we have to change because GoogleSource no longer let people upload binaries files to their repositories.

you can get TorstoiGit as you SVN client, It is almost identical to TorstoiSVN and it is also free

[pHySiQuE]

SVN seems to work fine with GitHub...I just got your latest update with it.

Any chance we can get an EXE for the demo sandbox, so I can try the car? I can't seem to compile the VS 2012 project.

[Julio Jerez]

I fixed the VS 2808 and VS 2012 project files.

Sync again and open C:\Development\newton-dynamics\applications\demosSandbox\projects\visualStudio_2012\demosSandbox_VSExpress.sln
it should build out of the box

[pHySiQuE]

Got it. That heavy vehicle is really interesting. The motion feels really real. It reacts really realistically, but it's not exaggerated, and the motion is perfectly smooth.

I couldn't judge the sports car as well without some rolling hills, but the gearbox felt really nice.

I will get this implemented in my engine pretty quickly and get some vehicle demos out.

[FSA]

Acually this is damn cool! A shame that no cars are in my game
Good work!

[Julio Jerez]

I couldn't judge the sports car as well without some rolling hills, but the gearbox felt really nice.
I will get this implemented in my engine pretty quickly and get some vehicle demos out.

The sport cars, is in fact a stress test, car are quiet difficult to simulated, but if cars are hard a Race car with realist characteristic are near impossible.
The reason super car posh the limit of what a car on wheels can actually do.
I am happy how this one turned out and I will add so more refinement.

I couldn't judge the sports car as well without some rolling hills, but the gearbox felt really nice.

I would not expect a high performance super car to behave nice on rolling terrain for various reasons. It is really close to the ground (few inches) so it will h\get stuck
The suspecting are really stiff. so it will jump all over the place, finally the engine is too powerful, the moment a tire lose even a small grip, it accelerate to the maximum.
This is the one case where the bad behavior is a Good thing. Remember super Car are hard to drive even for real people.
what you could do is and SUV, or a monster truck, or any suburban sedan type of car, those will so well on normal terrain.

The cool thing is that this vehicle model is very flexible it can simulate realistically rear wheel car, front wheel cars and all wheel cars without any problems.

if you impopmnet in you engine that more impart parts are.
1-The engine which is specified with 4 point on the engine curve.
idle torque, idel RPM
peak torque at peak RPM
force power are MX Power RPM
red Line power at red line RPM
the trick for a good engine internal combustion engine design is that the power at Max torque should be smaller the Power at max Power RPM, but the torque should be larger.
Those points you can get form any Car magazine

2The second most important part is the tire properties.
TIRE_LATERAL_STIFFNESS 20.0f
TIRE_LONGITUDINAL_STIFFNESS 1000.0f
TIRE_ALIGNING_MOMENT_TRAIL 0.5f

lateral stiffness is the value that make the car respond quick or slogging, Sport car tires has low profile a high lateral stiffness, (a value around 20 is normal, but you can play with the number at test)
longitudinal stiffness is the tire to produce longitudinal force, this value is akin to a spring contact. the higher the value the quick the car reach his max acceleration, but a very bug value make unstable just like an spring system.
Aligning torque tail is a parameter the measure torsional torque, it generate a torque the make the tire align to the direction of motion. value from 0 to 1 is common.
Those parameter are found in tire specification but they are hard to fine.
My recommendation is that you crate a dialog box in your game editor so that people can tune those values until the fell the right.

Next I will add the Flight model to the vehicle joint so ta is can implement stuff like hover crash, airplanes with retractable landing gears and helicopters.

[manny]

I will also contribute a ray-cast car once I have the time, it's very light on the CPU but has certain downsides

[Julio Jerez]

I do not suppose that you added your vehicle using the Vehicle Listener manager.
If not when you are ready to contribute it, let me know I would like to refactor it so that It can be and option in the Vehicle manage

The Vehicle Manager should to support many different kind of vehicle. I was planning to add flight model for an Airplane like a WWI fighter.
Or maybe I will add a Tracked vehicle first, I don't know yet

I would be nice if it had a lightweight RayCast vehicle that can be use for LOD or for people who has the need for a inexpensive vehicle model for example.
I was planning to add one, but if you have one already that can be a good start and we can polish it.

[manny]

I do not suppose that you added your vehicle using the Vehicle Listener manager.

No, it's currently tightly integrated in our engine. It also has it's own gearbox implementation and things of that nature, I will extract the code and send it to you but it'll be a while until I've got some free time on my hands.

[Julio Jerez]

Ok now to complete the picture, I added and all terrain lightweight military jeep to the heavy vehicle demo.
Both vehicle can be drive in the same demo by pressing the change vehicle Key.
these are just default settings, and even wit that still feels pretty good to drive it, basically I took the heavy truck and change the a lithe bit, I am sure that with more tuning is should feel awesome.

Anyway I hope people like it, and use it.