Hey,
I am working on an octapod project and I need IK for that. I found that need litte programm but I can't get it to work with diffrent leg sizes. It only seems to work when "a" and "b" are equal.

Has someone any idea how to solve that??
Thak you very much. because I tried it now for a really long time....


int sx,sy,ex,ey,hx,hy;
int armLength,ua,la;
float uad, lad;
void setup(){
size(500,500);
background(255, 224, 150);
sx = width/2;
sy = height/2;
armLength = int(width/5);
}

void draw(){
fill(255);
rect(0,0,width,height);
upperArm();
}

void upperArm(){
int dx = mouseX - sx;
int dy = mouseY - sy;
float distance = sqrt(dx*dx+dy*dy);

int a = armLength;
int b = armLength;
float c = min(distance, a + b);

float B = acos((b*b-a*a-c*c)/(-2*a*c));
float C = acos((c*c-a*a-b*b)/(-2*a*b));

float D = atan2(dy,dx);
float E = D + B + PI + C;

ex = int((cos(E) * a)) + sx;
ey = int((sin(E) * a)) + sy;
print("UpperArm Angle= "+degrees(E)+" ");

hx = int((cos(D+B) * b)) + ex;
hy = int((sin(D+B) * b)) + ey;
println("LowerArm Angle= "+degrees((D+B)));

stroke(255,0,0,100);
fill(240,0,0,200);
ellipse(sx,sy,10,10);
ellipse(ex,ey,8,8);
ellipse(hx,hy,6,6);
stroke(0);
line(sx,sy,ex,ey);
line(ex,ey,hx,hy);
}