RE: [Algorithms] floats, doubles, epsilons, joy

[Steve W. <Ste...@im...>]

> -----Original Message-----
> From: Jason Zisk [mailto:zi...@n-...]
> 
> I've been working on some collision stuff lately and I keep 
> running into problems with floating point inaccuracies.
> Specifically if the player is standing on top of a triangle,
> the distance should be zero, 
>

If it was zero then the bottom of the player and the top of the triangle
would occupy the same space...not what I would expect to happen.  Maybe if
you always keep objects a set distance away...like maybe .01 and still use
an epsilon like .00001 then objects at rest won't be triggering a collision
detection.

> 
> is doing floating point math with doubles much slower or
> have other unwanted side effects?
> 

I believe they take just as long if the code is running on a 64bit data bus
with a 64bit floating point unit.  The only side effect is when converting
types which will throw some variance in results...but your epsilon should
solve that.

Rockn-Roll