Hi,

I just saw that Toxi added a "Quaternion class with spherical interpolation" to toxi.geom.

I'm trying to make particles move around a sphere.
Everytime I set a new target position, for a particle to go to, the interpolation/motion restarts from the 'poles' of the sphere.

All the documentations I found about quaternions were helpful, but I do not seem to be able to put my head around quaternions still.

here is some code:

Code:

import processing.opengl.*;

import toxi.math.noise.*;
import toxi.math.waves.*;
import toxi.geom.*;
import toxi.math.*;
import toxi.math.conversion.*;
import toxi.geom.util.*;


Vec3D[] shell, target;
Quaternion[] targetQuat;
int numPart = 500;
int radius = 300;

void setup() {
 size(1024, 768, OPENGL);
 shell = new Vec3D[numPart];
 target = new Vec3D[numPart];
 targetQuat = new Quaternion[numPart];

 for (int i = 0; i < shell.length; i++) {
   shell[i] = new Vec3D().randomVector().scaleSelf(radius);
   target[i] = new Vec3D().randomVector().scaleSelf(radius);
   targetQuat[i] = new Quaternion(0.0f , new
Vec3D().randomVector().scaleSelf(radius));
 }
}

void draw() {
 background(10);
 translate(width/2, height/2);

 for (int i = 0; i < shell.length; i++) {
   pushMatrix();
   //JUST VECTOR
   //shell[i].interpolateToSelf(target[i], .01f);

   // QUATERNION
   Quaternion actualQuat = new Quaternion(0.0f, shell[i]);
   Quaternion newQuat = actualQuat.interpolateTo(targetQuat[i], .
01f);
   shell[i].set(newQuat.getValue()[1], newQuat.getValue()[2],
newQuat.getValue()[3]).scaleSelf(radius);

   translate(shell[i].x,shell[i].y,shell[i].z);
   ellipse(0, 0, 5, 5);
   popMatrix();
 }
}

void mousePressed(){
 for (int i = 0; i < target.length; i++) {
     //JUST VECTOR
     //target[i] = new Vec3D().randomVector().scaleSelf(radius);

     // QUATERNION
     targetQuat[i] = new Quaternion(0.0f , new Vec3D().randomVector().scaleSelf(radius));
 }
}
 

Thanks

//h