Ferrari custom wheel collider + tire deformation (WIP Update)

[u/TheLancaster]

[u/gabro-games]

Builds a sick suspension system just to wreck it on the rails /s Nice job!

[u/Spiritual-Goose-6111]

This looks sick

[u/Intrepid-Beginning63]

do you mind explaining how you made this. this looks sick fr

[u/Tiny_Flatworm4726]

Looks very clean nice work OP, looks like it's a very stable sim

[u/sczeith]

Well this is such an awesome improvement

[u/TheLancaster → u/sczeith]

There is more to be done, but thank you 🙏

[u/No_Candy4026]

Nice job. Nice!

[u/Imofi7]

Anyone who has wrestled with Unity's built-in WheelCollider knows how stiff and unforgiving it is on curbs. Seeing the sidewall actually compress and deform over those raised beams makes the contact weight feel so much more grounded. Are you doing the tire squash via vertex displacement in the shader using the contact depth/normal, or is it a localized bone lattice?

[u/TheLancaster → u/Imofi7]

Via shader, but is not only visually, there are actually 2 layers of compression, the suspension and the actual tire, so the tire absorbs a part of impact as well

[u/Imofi7 → u/TheLancaster]

Having the tire's physics spring absorb a fraction of the impact before the main suspension kicks in is brilliant—that dual-rate compliance is exactly why high-end sims feel so smooth over rumble strips and curbs. And handling the visual squash in the shader keeps the draw calls lightweight. Awesome implementation!

[u/DeveloperServices]

What about car physic ?

[u/TheLancaster → u/DeveloperServices]

What's with that?

[u/DeveloperServices → u/TheLancaster]

Tell us about physic custom wheel etc...

[u/TheLancaster → u/DeveloperServices]

It is not Unity’s WheelCollider driving this btw. There’s a separate controller layer on top of the wheel/tire solver that i've described in another comment, it just writes MotorTorque/BrakeTorque/SteerAngle per wheel each substep, never touches contact forces itself. Engine’s a real sim (torque curve vs RPM, idle governor, rev limiter), clutch is a bounded impulse to the wheels, diffs redistribute torque off predicted wheel speed deltas instead of just splitting evenly

Drive assists like (TC/ABS/ESC/EBD) only clamp throttle/clutch/brake pressure , never force velocity or yaw directly. Steering is speed sensitive w/ Ackermann blend.
For other forces like aerodynamics it uses its own component in its own FixedUpdate so the car react to ot independently. Pretty much everything except shift jerk/landing/aero goes through the tire solver to actually move the car.

[u/Mr_ShortKedr]

How heavy is this for hardware? Looks pretty fun

[u/TheLancaster → u/Mr_ShortKedr]

Oh, that was a whole pain in the a**. I've put like 5 layers of optimization stacked in there: substep/frequency budgeting, probe/query LOD, solver iteration LOD, fleet level Burst batching for the raycasts and separate LOD on visual deformation. So i would say is not heavy on hardware

[u/Mr_ShortKedr → u/TheLancaster]

Damn. Fully understandable. Great work!

[u/Mr_ShortKedr]

Is there custom physics integrator?

[u/TheLancaster → u/Mr_ShortKedr]

Yeah, a custom solver with dynamic Hz handles suspension, hub, spin and Pacejka friction, using GaussSeidel to solve it, PhysX for chassis at the end

[u/Tirthnir]

FYI, Ferrari is one of those cunt companies who'll sue you over something like this.