RaycastVehicle Behaviours

[andrezero]

Hey there 👋 first post here!

First of all, congrats for maintaining this project ❤️

Context: I am building a lo-poli driving studio app to create and share terrains, tracks, vehicles, the works 💪 ... with physics enabled, off course, and engine simulation based on real data

so far so good! most things are working great: engine idling, drivertain and gearbox ratios, engine choke, engine braking, - and the benchmarks even hit exact! max speeds and approx 0-100 performance 🤩

😬 I am sorry for dumping all these questions here (I am not even sure this is the right place ... Is there a community/discord somewhere?)

Questions:

1) What is the meaning of skidInfo, slipIndo and sliding?

It's hard to tell from the docs and testing it is also hard to make sense of how they jumn betweem 0-1 or NaN ...

2) isInContact is always false in my implementation ... any idea why?

Evertyhing else seems very reactive 👍 but this boolean never changes in my code.

🧪 Wasn't able to reproduce this in raycast_vehicle demo - here, the isInContact seems to be correctly alternate between false and true

I have actually inferred meanwhile if wheel is contact via the rather cryptic wheelInfo.slipInfo === 1 which I guess means _has zero adherence` ... 😬 ... err, maybe?

Anyway, is there an obvious way in which I am misusing vehicle/wheels for isInContact not to work?

3) Do I understand correctly that wheels have no innertia once they are not on the ground?

🧪 I was able to reproduce this in raycast_vehicle demo - here, wheels seem to show deltaRotation === 0 whenever wheelInfo.isInContact === false

4) Do I understand correctly that wheels lock as soon as braking force is bigger than engineForce?

🧪 Able to reproduce this in raycast_vehicle demo .. as soon as you press 'b', 'deltaRotation' drops to zero and the infos go skidInfo: 0.046, sliding: true, slipInfo: 1310.

For now I am controlling it on my side, just updating engineForce and distributing a negative force through the wheels according to my brake balance setup ... and when my sim decides, it sets the brakes to a force superior > engine force and the wheels (or some) do indeed lock on the RaycastVehicle side

Good strategy? Or am I missing something?

5) Why do vehicles seem to struggle uphill?

I am using a heightfield similar to the one in the demos, but the force transfer between vehicle and wheels seem to differ tremendously on the inclination of the terrain

• they benchmark well on flat terrain
• accelerate too fast downhill
• acceleratte like 🐌 uphill

are the rays informing the wheels of constant "collision" with the ascending terrain? and otherwise loosing contact/grip while going down hill?

os it just the effect of gravity? is there a way to dampen it somehow??

or are my engineForce values completely off-the mark (I somehow settled on Kw / 10 , for example -680 of engine braking force in the screenshot)

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maybe the following explains some of my issues?

🤔 ... why is deltaRotation negative when the force applied is positive? did I rotate the wheels wrong?

🤔 ... does wheel body mass have any effect? (my tests hint at no, not at all)

🤔... why are wheel collisions disabled wheelBody.collisionFilterGroup = 0; in the examples? I enabled and understood that wheels collide with the vehiclebody, but once I set correct filter/mask everything seems to be work fine collisionFilterGroup: COLLISION_GROUP_VEHICLE_WHEELS, collisionFilterMask: COLLISION_GROUP_TERRAIN but at the same time, nothing changed 😅 so I guess the raycasting does all the job and collisions should definitely be disabled for wheels?

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P.S.: anyone interested in the project? get in touch_ 🤗