Hello,
i’m traying to implement vehicles (tanks, actually) in our game, and have a problem i can’t fix. The effect is that the vehicle is very twitchy and sometimes not at all controllable. This is much more pronounced on tanks than wheeled vehicles. Examining the vehicle query data, i found that the longitudinal slip values are quite erratic. Here is an example of longitudinal slip for two front wheels of a tank, which should be going straight forward:
long_slip: -2.171 1.781
long_slip: -0.262 0.259
long_slip: 0.610 -0.260
long_slip: -1.755 1.158
long_slip: 0.216 -0.292
long_slip: -0.974 0.963
long_slip: 1.000 -0.352
long_slip: -2.203 1.218
long_slip: -0.114 -0.091
long_slip: 0.264 0.166
long_slip: -0.695 -0.216
long_slip: 0.815 0.267
long_slip: -1.829 -0.317
long_slip: 0.203 0.412
long_slip: -0.472 -0.879
long_slip: 0.739 0.518
long_slip: -0.790 -0.414
long_slip: 1.930 0.943
long_slip: 0.115 -0.421
long_slip: -0.207 0.625
long_slip: 1.496 -1.699
long_slip: -0.181 0.172
long_slip: 0.485 -0.242
long_slip: -1.637 1.369
long_slip: 0.281 -0.325
long_slip: -0.530 0.654
long_slip: 2.346 -2.013
long_slip: 0.491 -0.225
long_slip: -0.671 0.616
long_slip: 2.272 -2.107
long_slip: 0.536 -0.279
long_slip: -0.600 0.691
long_slip: 0.893 -0.771
long_slip: -2.158 2.493
long_slip: -0.399 0.718
long_slip: 0.811 -0.645
long_slip: -0.741 0.904
long_slip: 2.391 -2.148
long_slip: 0.665 -0.392
long_slip: -0.608 0.800
long_slip: 0.862 -0.729
long_slip: -2.077 2.370
long_slip: -0.355 0.656
long_slip: 0.739 -0.603
long_slip: -0.695 0.779
long_slip: 0.950 -0.625
long_slip: -2.147 2.056
long_slip: -0.349 0.467
long_slip: 0.734 -0.467
long_slip: -0.713 0.398
long_slip: 0.475 -0.297
long_slip: -1.528 0.534
long_slip: 0.213 -0.003
long_slip: -0.402 0.013
long_slip: 0.429 -0.002
long_slip: -1.532 0.013
long_slip: 0.424 0.116
long_slip: -0.520 -0.008
long_slip: 0.897 0.097
long_slip: -0.626 -0.006
long_slip: 2.081 -0.008
long_slip: 0.424 0.106
long_slip: -0.453 -0.040
long_slip: 0.690 0.136
long_slip: -0.522 -0.098
long_slip: 0.759 0.246
long_slip: -1.622 -0.569
long_slip: 0.039 0.688
As you can see, they are all over the place, causing the tank to jitter left-right, sometimes even causing it to turn and change direction even if no left-right control has been applied. I’ve verified that only the accelerate and thrust are applied, and that brakes are at zero. Wheel and surface materials have frictions and restitution set to 0.6.
I’ve compared the way my vehicles look in the Visual Debugger with the tank from the PhysX 3.3.4 samples, and can’t find significant differences.
Any help would be greatly appreciated.