Re: [Algorithms] Formula for Damping f times

[Alen L. <ale...@cr...>]

I guess you use this only if you run with fixed timestep of 20fps?

Aeln

Richard wrote at 6/9/2009:

> the only robust solution i have found to this situation has been to
> create a sub second k and apply it multiple times.

> float subTimeStep = 0.05f; // 20fps
> subK = exp(log(k)*subTimeStep);

> mUpdateTimer += deltaTime;
> while( mUpdateTimer > 0 )
> {
>   mUpdateTimer -= subTimeStep;
>   x = x*subK;
> }

> anything else either is slower, or has accuracy issues that make
> network code impossible to debug.

> 2009/6/5 Zafar Qamar <zaf...@co...>:
>> Hi,
>> This is a semi-trivial but I can't quite remember the answer, even
>> though I've done it before.
>>
>> I have an update function sort of like this..
>>
>> void updateX( float deltaTime)
>> {
>>        x = x*k;
>> }
>>
>> k is a constant less than 1.0.
>>
>> Now to do the damping properly I need to perform "x=x*k" deltaTime
>> times, where deltaTime is a fraction.
>>
>> Can anyone help with this please? I recall it just being a log or
>> something.
>>
>> Cheers
>> Zafar Qamar
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-- 
Alen