[Solved] Physics car tyre - remove lateral motion

So basically I have tried to translate this tutorial to C2 event system.

https://www.iforce2d.net/b2dtut/top-down-car

It seems that in the example it just applies an impulse to the center of the object.

void updateFriction() {
      b2Vec2 impulse = m_body->GetMass() * -getLateralVelocity();
      m_body->ApplyLinearImpulse( impulse, m_body->GetWorldCenter() );
  }[/code:c1txk97f]
If I use that Mass * -getLateralVelocity it is just way too much force. Also I tried to set velocity to lateral x and y with all kinds of variations, but could't get it to work.

Here is Youtube video from working car
[youtube video="Y"]

I think this should be the main idea.

I assume that could then be manipulated with some kind of friction value.

So far I basically just managed to get some values out.

You can push the tyre around with right mouse and rotate with left and right arrows.

Web test

CAPX

Maybe R0J0hound, Yann or keepee could point me to the right direction

Katala,

i was trying to do something like this a while ago:

https://dl.dropboxusercontent.com/u/53374990/Forum/car%20physics.capx

the group with the wheel physics should be open.. use WASD to control car, if you drive forward there is a row of unattached wheels where you can see how they don't laterally move.

I'm still not sure whether the physics is right, or whether it just needs fine tuning. Things like the collision polygon of the car, and wheel positions affect handling quite a lot.

I was trying to go for a car that you could drift reliably without losing control, but it wasn't really successful

I don't have time to check yet nor do I have time to download the 164.2 version, but following the reference page you posted, the lateral velocity formula should be:

currentRightNormalX = cos(car.Angle + 90)
currentRightNormalY = sin(car.Angle + 90)
dot = currentRightNormalX * car.Physic.VelocityX + currentRightNormalY * car.Physic.VelocityY
lateralVelocityX = dot * currentRightNormalX
lateralVelocityY = dot * currentRightNormalY[/code:29wqbxyj]

keepee, This is awesome! It seems to behave quite right. I think for "easy" drifting there should be somekind of spin prevention system.

Yann, This also works if I remove that +90 part.

Thanks a lot for helping me out! I can now continue to make some sort of weight tranfer and whatnot

Katala

That's very weird and suspicious.