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What kind of Inverse Kinematic is used here?

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I'm going to code some 3d creatures like snakes or tentacles.
For inspiration i've looked for some code around on the net and i've found this one:
ok, i like it.

It is a simple structure: a list of nodes, the first node is the main direction, the other nodes follow the first in a fluid and

wiggly way.

the algorithm is quite easy:

1 calculate the position of the head (the direction of the creature)
2 this procedure is used:

[source lang="java"]void move(float headX, float headY, float headZ) {

float dx, dy, dz, d;

// node 0: position, direction, orbiting handle
nodes[0].x = headX;
nodes[0].y = headY;
nodes[0].z = headZ;

// node 1: muscule
count += muscleFreq;
nodes[1].x = nodes[0].x ;
nodes[1].y = nodes[0].y + PApplet.sin(count) ;
nodes[1].z = nodes[0].z + PApplet.cos(count) ;

// apply kinetic forces down through body nodes
for (int i = 2; i < nodes.length; i++) {
dx = nodes.x - nodes[i - 2].x;
dy = nodes.y - nodes[i - 2].y;
dz = nodes.z - nodes[i - 2].z;

d = PApplet.sqrt(dx*dx + dy*dy + dx*dx) *ks;

float dx_d = + (dx * girth) / d;
float dy_d = + (dy * girth) / d;
float dz_d = + (dz * girth) / d;

nodes.x = nodes[i - 1].x +dx_d;
nodes.y = nodes[i - 1].y +dy_d;
nodes.z = nodes[i - 1].z +dz_d;

with girth as a random number near between 5 and 15 and muscleFreq between 0.1 and 0.2 i get nice results.

now, i understand that this is not the real inverse kinematics but.. if i check on google about IK i found a lot of maths and a lot of methods like angles, CCD, Jacobs..
my question is:
i just need to make wiggly creatures. what is this algorithm?
or even.. can you advice me some articles or other way to make chain snake-like creatures? Edited by nkint

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