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Car wheel rotation on an angle
Hi, hope someone can help.
I’ve got a car set up so that the wheels rotate when the car is moved left to right. But I can’t work out how to extend the expression so that the car may move on a diagonal path with the wheels rotating correctly.
Not sure if I explained that well, but imagine a car in 2D moving up and down the contours of a mountain. So not flat along the x-axis, but diagonally. Is there a way to modify the expression so the wheels rotate correctly?
I think it has something to do with trig, and working out the hypotenuse dynamically based on the slope/angle of the car and the distance travelled in x and y.
Thanks!
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3 Replies
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For an irregular path, you’ll probably have to calculate the length of terrain traversed frame by frame. I’d start with something like this:
accum = 0;
for (f = timeToFrames(inPoint); f <= timeToFrames(); f++){
t = framesToTime(f);
p0 = position.valueAtTime(t-thisComp.frameDuration);
p1 = position.valueAtTime(t);
accum += length(p1,p0);
}
accum*360/(Math.PI*width)
Dan
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Dan, thank you so much!!
After a little tweaking for my particular situation, that worked a dream.
Thank you sir,
Ben
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Sorry fo waking up this old lad…. can I make this work in 3D space too? how?
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