Rigging a Car

[throb36 0]

So I'm rigging a car (for my own shits and giggles, not a job).

 

And I want to use Xpresso entirely (no Dynamics).

 

Calculating the rotation or distance is easy enough. But only in a straight line.

 

Anybody know the math, or can point me in the right direction to solve distance/position when the cars wheels (heading) are turning.

 

 

[Mylenium 0]

You will have to use the history levels and iterate them backwards to accumulate the correct angles and based thereon the directional rotations. I think in fact there's an example for this in the Thinking Particles presets. Otherwise check the usual suspects like Base80 and so on. I'd most likely do it in Python. Beyond that I'm sure you could find enough math examples for Maya, MAX, Houdini, Unreal Engine, Unity or whatever and snatch pieces of the code. Basically one would calculate a multiplier based on the steering angle to slow down or accelerate the rotation of the inner and outer wheels, respectively. Or you could go super-exact and integrate those again by calculating the offset path from the car's center... Depends on the situation.

 

Mylenium

[iline 0]

I'm rigging a car at the moment, and I have switches to animate the wheels any speed I want, all four or individually, and then there's the calc to do it based on distance alone (align to spline makes this easy as hell). I hadn't thought about the question of outer wheels and differentials, if you find anything useful please share it!

[javier g 0]

if you have to do this for a real job, i would recomend the Drive! plugin for c4d, its amazing

[levante 0]

I'd be careful with the Drive plug-in. Its a nice toy but it can be annoying as hell, when the simulation isn't doing what you want it to or scrubbing backwards in the timeline doesn't update your viewport. Using this thing on a commercial project was one of the biggest mistakes i made in my “car-animation-career.”

If you want full control, you gotta be able to override every parameter with keyframes - so stay away from simulation or only use it on certain shots where you really need it.