1.8.0 sripted hinge disappear

[Kilinich]

1.8.0
I found this trying to build very fast servomotor. Run scene and see how whole arm disappear after a few moments.

No div by 0, no error in code. It juts disappear in some unpredictable moment.
Not happened on slow speed. Weired.

The only thing I've noticed - it happened then motor speed is near zero and switches 0/-0.

[scene]47345[/scene]

[Kilinich]

I've found the reason
And It's bad.

Shortly - because of algodoo not very precise sometimes, for example e.normal vector length can be 1.0000001

Then I try to calculate angle between current and last e.normals (call it n1 and n2) using formula
http://en.wikipedia.org/wiki/Dot_product

n1(0) * n2(0) + n1(1) * n2(1) = cos (a)
algodoo sometimes calculate it as 1.0000001 and math.acos() gives NaN.

I don't know how to handle it yet... maybe Emil can fix it somehow? for example change NaN result of arccos to 0 instead of NaN if argument > 1 (and same for other arc-functions) ?

[Kilinich]

even if motor speed set to NaN it's not good to remove script and motor ad everything it connect from scene..

[electronicboy]

I agree, algodoo should keep a bad object in the scene so it can be fixed by the author easily.
and if it is impossible to use the bad value, make algodoo restore a valid value like it does with the text box's in the script menu.

[emilk]

Clamp = (x, min, max) =>{ x < min ? min : x > max ? max : x };
Acos = (x)=>{ math.acos(Clamp(x, -1, +1)) };

[Kilinich]

Clamp = (x, min, max) =>{ x < min ? min : x > max ? max : x };
Acos = (x)=>{ math.acos(Clamp(x, -1, +1)) };

sure. but my scenes already lags like hell
so i prefer just * 0.999999