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Help with wheel bump

Posted: Tue Aug 02, 2011 11:48 pm
by elpin
Hello,

I'd welcome any help in the following matter:
A rigged truck frame and a planar ground with 3 bumps. I'd like the truck to go over the bumps to nicely see the suspension at play. Unfortunately I can't get the suspension to act realistic. The frame is bouncing together with the wheel too much. The frame needs to be more stable while only the wheel bouncing up and down. Is there any way to tweak this? Surprisingly suspension setting has no effect on this and the speed at which I drive over the bumps neither! When I look in slow motion at the recorded simulation the wheels and frame are bumping exactly the same way at quite different speeds.

I tried suspension stiffness 1000 and damping 200 and also stiffness 4000 and damping 800 and the result is identical. I also tried to change the mass multiplier but it also didn't change anything.

Here's a picture of the scene and another picture showing the rigging.
Image
Image

Is the rigging actually correct? In order to fit the long frame I had to scale the body quite big. Is it possible that it's influencing the result of the wheel bumps?

Also here's a video of the motion. As you can see the frame is just tilting sideways too much.
http://www.thelooopcgi.com/truck.avi

Thanks!
David

Re: Help with wheel bump

Posted: Fri Sep 09, 2011 2:22 pm
by Patrik Martin
The lower values you have on the suspension and damping you have the more "bouncy" effect you will have. If you like it to be totally stiff then you can just animate the body by hand and then add extrawheelse as wheels instead to just follow the ground.

Re: Help with wheel bump

Posted: Fri Sep 09, 2011 3:30 pm
by elpin
That's the thing with suspension settings. It works fine for the car braking, accelerating and turning, but when it comes to obstacles and ground bumps the suspension settings have very little effect.

But anyway, I achieved what I wanted by animating the car twice. Once with smaller bumps and then with bigger and merged the body and wheels together later. Thanks for the tip with adding extra wheels! Seems like it would be easier than animating the thing twice and merging.