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Falling too slow, should I increase gravity?

Start up a new project, setup a default size sphere (xyz scales are 1), attach rigidbody etc and look at how it falls,

The falling looks slow under default gravity, until I change gravity to -20 then it looks about right.

But changing the realistic gravity dont' seem to be the right thing to do? Does anyone know what might be wrong?

Thanks!

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asked Feb 11, 2011 at 04:05 AM

Rei gravatar image

Rei
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thanks for helping guys.. yeah I went through the rigid body reference page many times...

mass should not affect falling, (and I have tried it) ; then I made sure drag is set to 0. , and again size scales are all 1.

gravity of -9.81 still looks like it's falling about half of speed...

what else can be wrong..? or just I am delusional?...@_@

Feb 12, 2011 at 04:38 AM Rei

Probably your scale is too big; use a smaller scale.

Feb 12, 2011 at 04:47 AM Eric5h5

Rei, you may be delusional, but then we're two :)

I was doing a simple prediction of time-of-impact for a projectile and thought I had the math worked out correctly, but the projectile kept overshooting, I then used 9.81/2 as my gravity constant, and lo and behold: Everything added up.

I tried simulating the path myself using a kinematic rigidbody, but to match Unity's arc (when using a non-kinematic rigidbody with a constant velocity and gravity), I have to use half g.

Is it not just a simple 2nd order polynomial?

p = p0 + t*v + t^2 * g

What am I missing?

Jun 13 at 08:18 PM BoaNeo
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2 answers: sort voted first

Reduce the drag; see the docs about rigidbody behavior: http://unity3d.com/support/documentation/Components/class-Rigidbody.html

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answered Feb 11, 2011 at 04:28 AM

Eric5h5 gravatar image

Eric5h5
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I am missing that the speed of the curve is

p' = v + 2gt

I.e. double g... So, never mind, sometimes one just need to ask the question to see the answer :)

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answered Jun 13 at 09:05 PM

BoaNeo gravatar image

BoaNeo
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asked: Feb 11, 2011 at 04:05 AM

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Last Updated: Jun 13 at 09:05 PM