AI Driving - Feedback topic
They told me to explain what is new AI driving and how it works. We've been working on it for many months, in almost complete secrecy (excluding occasional Oukej talking about vacuum cleaners).
It is mandatory to mention, that it is still Work In Progress, has few bugs I know and many which I don't know about yet. Also, currently this new AI driving works only for wheeled vehicles, otherwise known as Cars.
Now let me try to convince you that it was worth waiting for. Motivation, so why we even bother Main issue we wanted to fix was AI's inability to drive the car through narrow streets of most of the cities without crashing, especially on tight corners and complicated junctions. Trying to solve those issues in broad aspect of driving behavior we found out, we need also to refactor big part of code, basically everything related to AI driving. This led to creation of new component class, which can be added and configured for each Car, and many other changes, movements, improvements and optimizations.
Finally, the purpose is to give us and mod-makers better ways to configure AI driving behaviors per vehicle, easier and more flexible ways for mission makers to control their AI, and precise and competent drivers for players to encounter. Execution, so how it is done Main point of new technology is a new component (AICarSteeringComponent), which encapsulates all related algorithms which steers the car. We chose to make it a component of Car, not AI agent or his brain, as tweaking of parameters of Component can happen per vehicle. In sense it defines driving behavior attached to type of vehicle, not a type of driver.
We managed to move and rework most of actions driver can do in game, simple path following, but also keeping formation, following in convoy, un-stucking himself or reacting to player direct commands. All of those had to be refactored, simplified, optimized and enclosed in mentioned component. In the heart of new driving, we have PID controllers, those are common but very flexible algorithms, for example used in engineering for temperature control, or in automated vehicles, for speed or altitude control. We use them for both speed and steering, also allowing modification of its parameters in config. Participation, so how you can use it As a player, you can join development branch users, run the editor and spawn yourself a Hunter and AI driver to command. You will see different driving style in any wheeled vehicle, be it a truck or tuned hatchback. Also, as it was enabled by default for all cars, vanilla or not, you should be able to see the new behavior in all old scenarios, missions wherever AI drives a car.
As a mission maker, or scripter, or if you just want to experiment more, you can still use script commands like: vehicle limitSpeed 15;
driver vehicle forceSpeed 40;
As a mod maker, you can configure your own vehicle and experiment with the config values directly: class AICarSteeringComponent { steeringPIDWeights[] = { 2.0, 0.2, 0.0 }; speedPIDWeights[] = { 0.5, 0.2, 0.0 }; doRemapSpeed = true; remapSpeedRange[] = { 10.0. 90.0 }; remapSpeedScalar[] = { 1.0, 0.35 }; doPredictForward = true; predictForwardRange[] = { 1, 20 }; steerAheadSaturation[] = { 0.01, 0.4 }; speedPredictionMethod = 2; wheelAngleCoef = 0.7; forwardAngleCoef = 0.7; steeringAngleCoef = 1.0; differenceAngleCoef = 1.0; stuckMaxTime = 3.0; allowOvertaking = true; allowDrifting = false; allowCollisionAvoidance = true; maxWheelAngleDiff = 0.2616; minSpeedToKeep = 0.1; }; Iteration, so what next It is still very much work in progress, and few additional improvements are planned. We are also aware that you can encounter some issues, especially on the beginning. Problem of unstucking is still very much open, as it's a challenge to find perfect algorithm for all the situations. We also will be looking into configuring different vehicles, and also how modders will try to use it, your feedback is not only welcomed, it's crucial. Please, report all problematic situations and places, but don't forget important information: type of vehicle, map, exact location, waypoint, order or any other way you are making AI drive. Screenshot with map coordinates and explanation of route is like, minimal data, required for us to analyze what could go wrong. You can also try pushing the AI, for example with "unit forceSpeed 40" which essentially overrides usual safe upper limit of speed, you can send multiple convoys across your islands and test the madness that ensues after, just don't forget to share those missions with us.
It is mandatory to mention, that it is still Work In Progress, has few bugs I know and many which I don't know about yet. Also, currently this new AI driving works only for wheeled vehicles, otherwise known as Cars.
Now let me try to convince you that it was worth waiting for. Motivation, so why we even bother Main issue we wanted to fix was AI's inability to drive the car through narrow streets of most of the cities without crashing, especially on tight corners and complicated junctions. Trying to solve those issues in broad aspect of driving behavior we found out, we need also to refactor big part of code, basically everything related to AI driving. This led to creation of new component class, which can be added and configured for each Car, and many other changes, movements, improvements and optimizations.
Finally, the purpose is to give us and mod-makers better ways to configure AI driving behaviors per vehicle, easier and more flexible ways for mission makers to control their AI, and precise and competent drivers for players to encounter. Execution, so how it is done Main point of new technology is a new component (AICarSteeringComponent), which encapsulates all related algorithms which steers the car. We chose to make it a component of Car, not AI agent or his brain, as tweaking of parameters of Component can happen per vehicle. In sense it defines driving behavior attached to type of vehicle, not a type of driver.
We managed to move and rework most of actions driver can do in game, simple path following, but also keeping formation, following in convoy, un-stucking himself or reacting to player direct commands. All of those had to be refactored, simplified, optimized and enclosed in mentioned component. In the heart of new driving, we have PID controllers, those are common but very flexible algorithms, for example used in engineering for temperature control, or in automated vehicles, for speed or altitude control. We use them for both speed and steering, also allowing modification of its parameters in config. Participation, so how you can use it As a player, you can join development branch users, run the editor and spawn yourself a Hunter and AI driver to command. You will see different driving style in any wheeled vehicle, be it a truck or tuned hatchback. Also, as it was enabled by default for all cars, vanilla or not, you should be able to see the new behavior in all old scenarios, missions wherever AI drives a car.
As a mission maker, or scripter, or if you just want to experiment more, you can still use script commands like: vehicle limitSpeed 15;
driver vehicle forceSpeed 40;
As a mod maker, you can configure your own vehicle and experiment with the config values directly: class AICarSteeringComponent { steeringPIDWeights[] = { 2.0, 0.2, 0.0 }; speedPIDWeights[] = { 0.5, 0.2, 0.0 }; doRemapSpeed = true; remapSpeedRange[] = { 10.0. 90.0 }; remapSpeedScalar[] = { 1.0, 0.35 }; doPredictForward = true; predictForwardRange[] = { 1, 20 }; steerAheadSaturation[] = { 0.01, 0.4 }; speedPredictionMethod = 2; wheelAngleCoef = 0.7; forwardAngleCoef = 0.7; steeringAngleCoef = 1.0; differenceAngleCoef = 1.0; stuckMaxTime = 3.0; allowOvertaking = true; allowDrifting = false; allowCollisionAvoidance = true; maxWheelAngleDiff = 0.2616; minSpeedToKeep = 0.1; }; Iteration, so what next It is still very much work in progress, and few additional improvements are planned. We are also aware that you can encounter some issues, especially on the beginning. Problem of unstucking is still very much open, as it's a challenge to find perfect algorithm for all the situations. We also will be looking into configuring different vehicles, and also how modders will try to use it, your feedback is not only welcomed, it's crucial. Please, report all problematic situations and places, but don't forget important information: type of vehicle, map, exact location, waypoint, order or any other way you are making AI drive. Screenshot with map coordinates and explanation of route is like, minimal data, required for us to analyze what could go wrong. You can also try pushing the AI, for example with "unit forceSpeed 40" which essentially overrides usual safe upper limit of speed, you can send multiple convoys across your islands and test the madness that ensues after, just don't forget to share those missions with us.
The "new driving stuff" is just the PIDs. Set useAISteeringComponent to false or delete the component class iirc (inherited all the way from Car_F base class) and you're back to the "old driving". But there are many other things that can influence or be the cause of AI driving issues (see at the bottom).
The oscillations around the ideal path have been always around in Arma 3 and were usually "caused" by a strong (good enough) braking power. In the "old driving" we simply solved it by making the brakes deliberately weak(er).
In the "new driving" one should be able to tune the AI driving (PID controllers) well together with any vehicle steering, accelerating or braking capabilities. Even with some driving style (casual, racing) in mind. At least in theory. In the old driving the AI posed strict limits to what one could do with the configuration of the vehicle handling.
I can't ask you to "fix it for us" but I'd still humbly ask anyone to try setting up the PIDs themselves (info in the first thread post). If you find values that give better results please share them with us and we'll be more than happy to adjust the configs.
Otherwise, from top of my head - in Tanks and in the previous patch - there have been several changes which may have had some impact on the AI driving * PhysX lib update * Switch from raycast to sweep queries and wheel colliders
* Adjusted surface frictions (generally lowered)
* Small changes to AIpathOffsets on roads
* Various AI driving fixes * And for Hatchback specifically also a complete overhaul (that's why the blame;)) of it's PhysX configuration. Other overhauled vehicles were the tracked ones, the kart, Hatchback, Zamak and also wheeled APCs to a degree. Using e.g. Hunter for testing would rule out these overhauls as a possible cause.
The oscillations around the ideal path have been always around in Arma 3 and were usually "caused" by a strong (good enough) braking power. In the "old driving" we simply solved it by making the brakes deliberately weak(er).
In the "new driving" one should be able to tune the AI driving (PID controllers) well together with any vehicle steering, accelerating or braking capabilities. Even with some driving style (casual, racing) in mind. At least in theory. In the old driving the AI posed strict limits to what one could do with the configuration of the vehicle handling.
I can't ask you to "fix it for us" but I'd still humbly ask anyone to try setting up the PIDs themselves (info in the first thread post). If you find values that give better results please share them with us and we'll be more than happy to adjust the configs.
Otherwise, from top of my head - in Tanks and in the previous patch - there have been several changes which may have had some impact on the AI driving * PhysX lib update * Switch from raycast to sweep queries and wheel colliders
* Adjusted surface frictions (generally lowered)
* Small changes to AIpathOffsets on roads
* Various AI driving fixes * And for Hatchback specifically also a complete overhaul (that's why the blame;)) of it's PhysX configuration. Other overhauled vehicles were the tracked ones, the kart, Hatchback, Zamak and also wheeled APCs to a degree. Using e.g. Hunter for testing would rule out these overhauls as a possible cause.
