A very good plugin. I want to simulate a car. How should I get it?

[baimengmengmeng]

I am an illusionary beginner with poor English, please don't mock me. I can use Unreal's built-in physics engine, but Unreal's own physics engine has poor calculation accuracy. How should I use your bullet? For example, if I want to simulate the physics of a car, is it the same as using Unreal? Or how to set it up? Where to set the friction, gravity, and power of the wheels?

[Yadhu-S]

Hello @baimengmengmeng,

Thanks for trying out the plugin.

There is no direct drop in vehicle implementation for this plugin as there is in UE with chaos. However, you can easily setup one on your own. The custom UBulletSkeletalMeshComponent is what I would start with.

• Set up your own collision for it (Physics Asset).
• Create RayCast springs and attach it to the four corners. spring calculations
• Add Constraints to keep it from rolling sideways (Friction can be adjusted here. Scale the force given by the constraint).
• Finally add a force to push the car on you UBulletSkeletalMeshComponent (Simplest way is to just fetch the amount of force from a graph based on speed. Give max power at slow speeds, and reduce the force as you speed up)
• Rolling friction, aerodynamic drag etc can be faked by adding force based on speed.

You can search around for "RaycastVehicles" on YouTube, it's a well established method and I'm pretty sure there is tons of documentation which will give you a general idea.

this looks like a good place to start. Follows the same ideas I believe.

PS: If were hoping to implement something that is a full blown simulation with tyre wear, deformation, track degradation, and so on... you still can do that, but would be a real challenge.

Hope this helps. Good luck :)

[Bigbossbro08]

Hi there! do you happened to have discord server or somewhere I can chat? I want to implement in my project with ECS(flecs) but integrating to it could be complicated. Mind if I can talk about it somewhere indepth?

[Yadhu-S]

Hello @Bigbossbro08 .

Sorry, I am unfamiliar with flecs. You will have to write your own integration for that. This is just a plugin for Unreal Engine to use bullet3 physics.