• Create Account

## What kind of Inverse Kinematic is used here?

Old topic!

Guest, the last post of this topic is over 60 days old and at this point you may not reply in this topic. If you wish to continue this conversation start a new topic.

No replies to this topic

### #1nkint  Members

103
Like
0Likes
Like

Posted 12 July 2012 - 05:21 AM

Hi!
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:
http://www.openproce...org/sketch/8405
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[i].x - nodes[i - 2].x; dy = nodes[i].y - nodes[i - 2].y; dz = nodes[i].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[i].x = nodes[i - 1].x +dx_d; nodes[i].y = nodes[i - 1].y +dy_d; nodes[i].z = nodes[i - 1].z +dz_d; } }[/source]

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, 12 July 2012 - 05:59 AM.

Old topic!

Guest, the last post of this topic is over 60 days old and at this point you may not reply in this topic. If you wish to continue this conversation start a new topic.