traer.physics fixed / rigid connection of particles

flokuehnle

traer.physics fixed / rigid connection of particles

in Contributed Library Questions • 3 years ago

hi,

i wonder if it's possible to connect three or more particles rigidly in traer.physics.
so that 3 particles behave like a seesaw, where the middle point is fixed, and the left and right move always in opposit directions, and keep their distance to the middle.

i could construct a cross from 5 particles, and very strong springs inbetween everywhere, but it looks like a bit clumsy solution...

any ideas?

thaks, best regards, florian.

Replies(6)

cedrickie..

Re: traer.physics fixed / rigid connection of particles

3 years ago

yes, should definitely possible. but i am still not 100 % sure what you are aiming for. maybe you can post what you have done so far and explain what you exactly need...
I will give it a try then.

flokuehnle

Re: traer.physics fixed / rigid connection of particles

3 years ago

well, i want to make a rigid stick that can rotate around it's center; on every of it's ends there is a "pendulum" hanging, a mass on a string.

import traer.physics.*;
ParticleSystem physics;
Particle anchor;
Particle pl, pr, pu, pd;
Spring sa, sb, sc, sd, se, sf, sg, sh, sx, sy;
Particle p1, p2, p3;
Spring s1, s2, s3;
int centerX = 400;
int crossSize = 100;
void setup()
{
size( 1000, 900 );
smooth();
fill( 0 );
ellipseMode( CENTER );
physics = new ParticleSystem( 0.5, 0.001 );
anchor = physics.makeParticle( 1.0, width/2, centerX, 0 );
anchor.makeFixed();
pl = physics.makeParticle( 1.0, anchor.position().x()-crossSize, anchor.position().y(), 0 );
pr = physics.makeParticle( 1.0, anchor.position().x()+crossSize, anchor.position().y(), 0 );
pu = physics.makeParticle( 1.0, anchor.position().x(), anchor.position().y()-crossSize, 0 );
pd = physics.makeParticle( 1.0, anchor.position().x(), anchor.position().y()+crossSize, 0 );
sx = physics.makeSpring( pl, pr, 1.7, 0.8, 3*crossSize );
sy = physics.makeSpring( pu, pd, 1.7, 0.8, 3*crossSize );
sa = physics.makeSpring( pl, anchor, 0.99, 0.8, 0.5*crossSize );
sb = physics.makeSpring( pr, anchor, 0.99, 0.8, 0.5*crossSize );
sc = physics.makeSpring( pu, anchor, 0.99, 0.8, 0.5*crossSize );
sd = physics.makeSpring( pd, anchor, 0.99, 0.8, 0.5*crossSize );
se = physics.makeSpring( pl, pu, 0.99, 0.8, sqrt(sq(crossSize)));
sf = physics.makeSpring( pu, pr, 0.99, 0.8, sqrt(sq(crossSize)));
sg = physics.makeSpring( pr, pd, 0.99, 0.8, sqrt(sq(crossSize)));
sh = physics.makeSpring( pd, pl, 0.99, 0.8, sqrt(sq(crossSize)));
p1 = physics.makeParticle( 0.4, pl.position().x(), pl.position().y()+180, 0 );
p2 = physics.makeParticle( 0.4, pr.position().x(), pr.position().y()+180, 0 );
p3 = physics.makeParticle( 0.4, pd.position().x(), pd.position().y()+180, 0 );
s1 = physics.makeSpring( pl, p1, 0.3, 0.3, 150 );
s2 = physics.makeSpring( pr, p2, 0.3, 0.3, 200 );
s3 = physics.makeSpring( pd, p3, 0.3, 0.3, 100 );
}
void mousePressed()
{
p1.makeFixed();
p1.position().set(mouseX, mouseY, 0);
}
void mouseDragged()
{
p1.position().set(mouseX, mouseY, 0);
}
void mouseReleased()
{
p1.makeFree();
}
void keyPressed()
{
if (key == 's') {
p1.velocity().add (random(-25.0, 25.0), random(-25.0, 25.0), 0 );
p2.velocity().add (random(-25.0, 25.0), random(-25.0, 25.0), 0 );
p3.velocity().add (random(-25.0, 25.0), random(-25.0, 25.0), 0 );
}
}
void draw()
{
background( 255 );
ellipse( anchor.position().x(), anchor.position().y(), 5, 5 );
ellipse( pl.position().x(), pl.position().y(), 10, 10 );
ellipse( pr.position().x(), pr.position().y(), 10, 10 );
fill( 200 );
ellipse( pu.position().x(), pu.position().y(), 10, 10 );
ellipse( pd.position().x(), pd.position().y(), 10, 10 );
fill( 0 );
line( pl.position().x(), pl.position().y(), anchor.position().x(), anchor.position().y() );
line( pr.position().x(), pr.position().y(), anchor.position().x(), anchor.position().y() );
line( pu.position().x(), pu.position().y(), anchor.position().x(), anchor.position().y() );
line( pd.position().x(), pd.position().y(), anchor.position().x(), anchor.position().y() );
ellipse( p1.position().x(), p1.position().y(), 20, 20 );
line( pl.position().x(), pl.position().y(), p1.position().x(), p1.position().y() );
ellipse( p2.position().x(), p2.position().y(), 20, 20 );
line( pr.position().x(), pr.position().y(), p2.position().x(), p2.position().y() );
ellipse( p3.position().x(), p3.position().y(), 20, 20 );
line( pd.position().x(), pd.position().y(), p3.position().x(), p3.position().y() );
physics.tick();
}

best regards, florian

cedrickie..

Re: Re: traer.physics fixed / rigid connection of particles

3 years ago

hmm maybe i still dont get it, but istn this exactly what you already got?
except that you have to remove some of the strings?

but i like what you got right now, fun to watch :)

flokuehnle

Re: traer.physics fixed / rigid connection of particles

3 years ago

yes to me it's also already funny...

and right, it basically goes where i wanted to go. except that the rotating cross is a little bit elastic, too. you notice it when you pull the one partical far away with the mouse. basically i wanted to have a rigid line in the middel; where only on the left and right thee are two pendula. but with the cross isn't bad as well.

if you remove strings, the cross collapses quickly. try it.

cedrickie..

Re: Re: traer.physics fixed / rigid connection of particles

3 years ago

oh ok, will test it. lets see how far i get.

cedrickie..

Re: traer.physics fixed / rigid connection of particles

3 years ago

so this isnt working for you? or would that be ok?

import traer.physics.*;
ParticleSystem physics;
Particle anchor;
Particle pl, pr ;
Spring sa, sb, sc, sd, se, sf, sg, sh, sx, sy;
Particle p1, p2 ;
Spring s1, s2, s3;
int centerX = 400;
int crossSize = 100;
void setup()
{
size( 1000, 900 );
smooth();
fill( 0 );
ellipseMode( CENTER );
physics = new ParticleSystem( 0.5, 0.001 );
anchor = physics.makeParticle( 1. , width/2, centerX, 0 );
anchor.makeFixed();
pl = physics.makeParticle( 1. , anchor.position().x()-crossSize, anchor.position().y(), 0 );
pr = physics.makeParticle( 1. , anchor.position().x()+crossSize, anchor.position().y(), 0 );
sx = physics.makeSpring( pl, pr, 1.7, 0.8, 3*crossSize );
sa = physics.makeSpring( pl, anchor, 3. , 1.8, 0.5*crossSize );
sb = physics.makeSpring( pr, anchor, 3. , 1.8, 0.5*crossSize );
p1 = physics.makeParticle( 0.4, pl.position().x(), pl.position().y()+180, 0 );
p2 = physics.makeParticle( 0.4, pr.position().x(), pr.position().y()+180, 0 );
s1 = physics.makeSpring( pl, p1, 0.3, 0.3, 150 );
s2 = physics.makeSpring( pr, p2, 0.3, 0.3, 200 );
}
void mousePressed()
{
p2.makeFixed();
p2.position().set(mouseX, mouseY, 0);
}
void mouseDragged()
{
p2.position().set(mouseX, mouseY, 0);
}
void mouseReleased()
{
p2.makeFree();
}
void keyPressed()
{
if (key == 's') {
p1.velocity().add (random(-25.0, 25.0), random(-25.0, 25.0), 0 );
p2.velocity().add (random(-25.0, 25.0), random(-25.0, 25.0), 0 );
}
}
void draw()
{
background( 255 );
ellipse( anchor.position().x(), anchor.position().y(), 5, 5 );
ellipse( pl.position().x(), pl.position().y(), 10, 10 );
ellipse( pr.position().x(), pr.position().y(), 10, 10 );
fill( 200 );
fill( 0 );
line( pl.position().x(), pl.position().y(), anchor.position().x(), anchor.position().y() );
line( pr.position().x(), pr.position().y(), anchor.position().x(), anchor.position().y() );
ellipse( p1.position().x(), p1.position().y(), 20, 20 );
line( pl.position().x(), pl.position().y(), p1.position().x(), p1.position().y() );
ellipse( p2.position().x(), p2.position().y(), 20, 20 );
line( pr.position().x(), pr.position().y(), p2.position().x(), p2.position().y() );
physics.tick();
}

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