[prog. in c] how to make stable paricles

[fir]

see that simulation

there is a group of lights/dots/balls/points (say atoms) and such fotces
are applied
1) if the ball is into wall apply a force proportional to depth of
being into wall

point[i].vx -= H* wall_penetration_x ;
point[i].vy -= H* wall_penetration_y ;

2) if the ball is to much close to other ball same the force related to
depth of penetration is applied (though here its square)


point[i].vx+= (dx/dist)* (n_pen*B)*(n_pen*B) /point[i].mass ;
point[i].vy+= (dy/dist)* (n_pen*B)*(n_pen*B) /point[i].mass ;


i chose it partially conceptually - knowing a=F/m - and partially
experimantally..it work wery well imo

the problem is i want to apply some ball-ball force additional to
this repeling one that would make those ball build in a kinda multi-ball
relativly stable "particles" ... and the question is what this force
should be?

here above on this video the lines you see are drawed when this third
force start to work.. (so teh lines arre kinda optical debug showing
how it work) i applied some but the particles that forms are much to
dynamical, oscilate llike crazy then sometimas shot one of atoms out and
so on

and i need a stable one

i experimented with this additional link force but not much
what i experimented was like adding link it is attraction force
that enebles when two points are closer than 1.5*link distance, which is
20 units (pixels) it is this attract force work on distance closer than
30 pixels

the force is something like

double link_dist = 20;
double dx = point[i].x - point[n].x;
double dy = point[i].y - point[n].y;
double Mi = point[i].mass;

double dist = sqrt(dx*dx + dy*dy );

if(dist>link_dist*1.5) return;

double L = 1.;
double p = (dist - link_dist)*L;

point[i].vx+= -(dx/dist)*(p*p)*sign(p)/point[i].mass;
point[i].vy+= -(dy/dist)*(p*p)*sign(p)/point[i].mass;

if(!m_toggler)
DrawLine2d(point[i].x, point[i].y, point[n].x, point[n].y,0xffffff );

but as i said the results are to messy and i need stable little "solid
bodies" i mean more "stiff" particles

some ideas as to what this link force should be?

[fir]

Post by fir
see that simulation
http://youtu.be/pP-uCjLp3RY

LOL, sorry for that sound it was by assidnt sound of the youtobe
movie i watched in background and i new in this program to make youtube
videos

[fir]

btw as i learned make ytb videos check put a movie of one of the first
demos compiled by my furia compiler under construction (which make
asembly tahat asembled my org-asm assembler)..thsi demu is compiled by
furia but it uses my green-fire dll library which contains a code for
per pixel rasterizer where i can test simple 2d/3d codes rendered by my
routines all on cpu

this few years old o worked on this when i wrote on thsi already here -
the source of this must also be in that posts..recently i got not much
power to code as getting old :c (but eventually should finish the compiler)

[fir]

Post by fir
see that simulation
http://youtu.be/pP-uCjLp3RY
there is a group of lights/dots/balls/points (say atoms) and such fotces
are applied
1) if the ball is into wall apply a force proportional to depth of
being into wall
      point[i].vx -= H* wall_penetration_x ;
      point[i].vy -= H* wall_penetration_y ;
2) if the ball is to much close to other ball same the force related to
depth of penetration is applied (though here its square)
   point[i].vx+= (dx/dist)* (n_pen*B)*(n_pen*B) /point[i].mass ;
   point[i].vy+= (dy/dist)* (n_pen*B)*(n_pen*B) /point[i].mass ;
i chose it partially conceptually - knowing a=F/m - and partially
experimantally..it work wery well imo
the problem is i want to apply some ball-ball force additional to
this repeling one that would make those ball build in a kinda multi-ball
relativly stable "particles" ... and the question is what this force
should be?
here above on this video the lines you see are drawed when this third
force start to work.. (so teh lines arre kinda optical debug showing
how it work) i applied some but the particles that forms are much to
dynamical, oscilate llike crazy then sometimas shot one of atoms out and
so on
and i need a stable one
i experimented with this additional link force but not much
what i experimented was like adding link it is attraction force
that enebles when two points are closer than 1.5*link distance, which is
20 units (pixels) it is this attract force work on distance closer than
30 pixels
the force is something like
 double link_dist = 20;
  double dx = point[i].x - point[n].x;
  double dy = point[i].y - point[n].y;
  double Mi = point[i].mass;
  double dist = sqrt(dx*dx + dy*dy );
 if(dist>link_dist*1.5) return;
  double L = 1.;
  double p =  (dist - link_dist)*L;
    point[i].vx+= -(dx/dist)*(p*p)*sign(p)/point[i].mass;
    point[i].vy+= -(dy/dist)*(p*p)*sign(p)/point[i].mass;
  if(!m_toggler)
   DrawLine2d(point[i].x, point[i].y, point[n].x, point[n].y,0xffffff );
but as i said the results are to messy and i need stable little "solid
bodies" i mean more "stiff" particles
some ideas as to what this link force should be?

note as to "stiff" particles (not sure as to this word becouse weak
english) they are possible as check some of my old demo

this 9 dot "Rectangle" is made by simple 1-1 link forces but the
difference is i set up those initial distances like 100 and sqrt (100) =
141.42 and so on by hand from init function in code

and this is very tiresome to set upo by hand so i think it would be give
some force that works liek chemistry it is glues that balls together
naturall way not by tedious set up

- but its the proof that it is generaly possible to have stiff particles
(more to say its making like rotating objests with angular momentum
without any code of angular momentum just simple lineas bal-ball forces
and newtonian a=F/m)