Count current velocity of geom for ABS

[hiltropper]

hi
i am new at this forum and i can not guarantee a perfect english

my problem :
im working on an anti blocking system (ABS we call it in germany) that controlls the wheels of a car.
everything works but one thing could be better : I change a scene.my.var with onlaserhit AND now what i want: the fade dist of this laser should have the same value as the speed of the car.so i thought i point with another laser at one geom from my car and let it count its current velocity on hit by this one laser and this current vel is equal to scene.my.var2 (that would be the fade dist of the ABS laser). -> If you drive fast , long dist ,if you dont move no (or in real very minimal) dist .
how is it possible to count the current velocity?
thanks for help!

[Rideg]

Just to make this clear for me. Do you want the speed or the velocity (velocity = [x, y]; speed = x)

[hiltropper]

velocity would be better (for driving on a slope)

[Rideg]

Make a box and a laser. (laser hits to the box)

This code will get you the velocity of your mouse cursor but you can make a box + laser on the car and in the box's onHitByLaser you type: (e)=>{scene.my.carpos = e.pos}

Then you can replace all app.mousePos with scene.my.carpos

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(e)=>{
    scene.my.vel = (app.mousePos - [color(0), color(1)]) / (sim.time - color(2));
    color = [app.mousePos(0), app.mousePos(1), sim.time, 0.6]
}

Hope it was what you were looking for

-Johan

[hiltropper]

thanks , its working!
final script

Code: Select all

(e)=>{
    scene.my.carpos = e.pos;
    scene.my.vel = (scene.my.carpos - [color(0), color(1)]) / (sim.time - color(2));
    color = [scene.my.carpos(0), scene.my.carpos(1), sim.time, 0.6]
}


but why has it something to do with the color?
its not really important but if you could explain it in short sentences it were nice

one last thing : would you please explain to me how to express an amount in algodoo ( i just know the way to write it " |x| " )
i only need the keys to write that in algodoo nothing else maybe you know.
thank you so far

[KarateBrot]

it has nothing to do with the color. he just used the color array to store data. the geometry does change the color over time but if you hide it it won't matter. instead you could also use another variable/array which you or your object doesn't need or you could make arrays for position and time + a variable for velocity. it's just a matter of taste

[hiltropper]

Du bist aus Deutschland ? Kannst du mir sagen wie ich in algodoo einen Betrag ( |x| ) ausdrücken kann ?
Das mit dem color dachte ich mir schon weil der sich die ganze Zeit geändert hat.
i already thought the color saved a value for a moment i just wondered why espacially the color has been taken for this.

[KarateBrot]

ja da machste einfach eine funktion dafür. wenn du etwas zum quadrat nimmst wird es immer positiv. dann nur noch die wurzel ziehen um wieder den ausgangswert zu haben.
öffne die konsole (F11) und deklariere eine neue funktion

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scene.my.betrag := (x) => { (x^2)^0.5 }


dann kannst du die funktion in deiner szene für alles verwenden. du schme9ßt einen wert in die funktion und bekommst den betrag raus. zum beispiel:

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scene.my.betrag(-3)
scene.my.betrag(irgendnevariable)


das kannst du auch in der konsole testen. das mach ich zumindest oft bevor ich was irgendwo in algodoo einprogrammiere.

- - - - -

i just explained how to make an absolute function

[kilebantick]

Good job Karate

[hiltropper]

gut funktioniert ,danke-
everything clear
thanks!