Edy’s Vehicle Physics live demo

Physically realist, stable and fun vehicle physics in Unity / PhysX

4 vehicles: Pickup / GTA4-Pickup / Bus / Sport Coupe (select with PgUp / PgDown).
Driving aids. Vehicle damage. Visual tire effects.
Press H for help or see below.

Arrows / WSAD – Accelerate, brake, turn
Space – handbrake
Return – unflip car
shift R – repair damage

PgUp / PgDown – select vehicle

12345 – ABS, TC, ESP, 4×4, Stabilization
E – eject payload
R – restart demo
T – slow motion

C – camera (also F1-F6)
V – secondary camera
M – minimap
N – mirrors (bus driver only)
B – telemetry
shift B – tire telemetry

Mouse – move view in cameras F1, F3, F5
NumPad – move camera position in F5

F12 – toggle low quality mode
Gears: Changing from forward (D) to reverse (R) and vice-versa requires the car to completely stop and then release both accelerate and brake keys, then press accelerate (forward) or brake (reverse). This behavior can be customized for each project (see the documentation for the CarMain script).¿Vehicle not going in a straight line? Surely it has received some damage at the wheels and lost their alignment. Press shift-R for repair.

Recent changes :
– Reflective car paint.
– Smooth movements on all cameras.
– Driver’s view (F1) now simulates the head and neck movement.

Advanced: Telemetry data (B key at the demo):

WheelFL, FR, RL, RR: data for front – rear, left – right wheels
– RPM: wheel spin in revs per minute.
– S: spring extension. 0 is fully compressed, 1 is fully extended.
– F: force supported by the spring in Newtons.
– FS: tyre’s forward slip (m/s)
– SS: tyre’s sideways slip (m/s)
– FSR: tyre’s forward skid ratio (<1 ok, 1..2 loosing grip, >2 skidding)
– SSR: type’s sideways skid ratio

Friction F, S: forward/sideways slip peak and asymptote.
Grip F, R: forward/sideways grip ratio
Stab F, R: force ratio transfered by the front – rear stabilizer bars
Steer L, R: steering angle for each wheel

Speed: forward speed in m/s, km/h and mph
– Abs: absolute velocity of the rigidbody (m/s)
– Lat: sideways velocity of the rigidbody (m/s)
– Acc: acceleration of the rigidbody (m/s2)

Pitch: forwards angle (typically changes when accelerating and braking)
Roll: sideways angle (typically changes when steering).
AngV: pitch/roll change rate with their higher reached values

Gear: current gear, D (drive), N (neutral) or R (reverse).
Accel, Brake, Handbrake, Steer: user’s input to pedals and steering wheel.
MotorMax, BrakeMax: maximum motor and braking torque applied to the wheels.

StabMode: stabilizer bars stiffness: auto, offroad, comfort, sport, none (5)
ABS: Antilock Brake System (1)
TC: Traction Control (2)
ESP: auto-steering angle limiter (3)
4×4 / front / rear: current traction axle (4)
Slow-Motion: slow time scale is enabled (T)

Tyre telemetry (B, then shift-B):

Forwards and sideways friction curves per each wheel, with their extremum and asymptote values. The horizontal scale is the tire slip in m/s. Forward and sideways slip values are shown in realtime:
– Green: slip is ok, the extremum value has not been reached.
– Yellow: slip is between extremum and asymptote. Tire force is decreasing.
– Red: slip has surpassed the asymptote value. Tyre force is the minimum (skidding).

Suspension and stabilizer bars are exposed in the right-most graphs:
– Wheels: the left bar shows the suspension travel, the right one the suspension force. Yellow means the suspension force has exceeded the spring value, and red means the suspension has reached its travel limit and it’s fully compressed so hard contact points are created.
– Stabilizer bars: the horizontal scale is the relative roll for that axle (0 = no roll, 1 = maximum roll before the inner wheel lifts from the ground) and the curve means the amount of force the stabilizer bar is exerting. Yellow means the force has exceeded the 50%, red means the force has exceeded the 75%.