Randomizing images as textures in 3D solids

Well, I have 30 solids and I have a different image for each of them. I created an array for the images, and if I choose to use the same image at all (as I left here in the code, use bandeira [0] ) it runs and everything is fine!

I now want to do a random that runs through the array of images and assigns a different image to each of the solids, but for some reason when I tried to% % - and stay with (int index = int(random(0, bandeira.length)); instead of index ) it continues to create all solids with the same image.

MAIN

int numPaises = 30;

float theta = 0;
PImage logo, chao;
PShape pessoa;

Paises [] solidos = new Paises [numPaises];  //Array solidos!

PImage[] bandeira = new PImage[30];


void setup() {

  bandeira[0] = loadImage("portugal.jpg");
  bandeira[1] = loadImage("espanha.jpg");
  bandeira[2] = loadImage("franca.jpg");
  bandeira[3] = loadImage("italia.jpg");
  bandeira[4] = loadImage("inglaterra.jpg");
  bandeira[5] = loadImage("alemanha.jpg");
  bandeira[6] = loadImage("brasil.jpg");
  bandeira[7] = loadImage("estadosUnidos.jpg");
  bandeira[8] = loadImage("china.jpg");
  bandeira[9] = loadImage("russia.jpg");
  bandeira[10] = loadImage("quenia.jpg");
  bandeira[11] = loadImage("argelia.jpg");
  bandeira[12] = loadImage("africaSul.jpg");
  bandeira[13] = loadImage("armenia.jpg");
  bandeira[14] = loadImage("austria.jpg");
  bandeira[15] = loadImage("bahamas.jpg");
  bandeira[16] = loadImage("belgica.jpg");
  bandeira[17] = loadImage("benin.jpg");
  bandeira[18] = loadImage("bulgaria.jpg");
  bandeira[19] = loadImage("chile.jpg");
  bandeira[20] = loadImage("congo.jpg");
  bandeira[21] = loadImage("cuba.jpg");
  bandeira[22] = loadImage("filandia.jpg");
  bandeira[23] = loadImage("jamaica.jpg");
  bandeira[24] = loadImage("noruega.jpg");

  size (1200, 650, P3D);

  for (int j=0; j < solidos.length; j++) {
    float angle = j * TWO_PI / numPaises;
    float x = 0 + 2000 * cos(angle);  
    float z = 0 + 2000 * sin(angle);
    int index = int(random(0, bandeira.length));     // *******
    solidos[j] = new Paises(x, 700, z, bandeira[0]);
  }
}

void draw() {

  background (0);

  scale(0.8); //escala de visão
  translate(700, 0, -3500);

  for (int j =0; j < solidos.length; j++) {
    solidos[j].render();
  }

  theta += 0.020;
}

CLASS COUNTRIES

class Paises {
  float x, y, z;
  float w, h, d;

  //CONSTRUTOR

  Paises(float nx, float ny, float nz, PImage img ) {
    x =nx;
    y = ny;
    z =nz;
    w= random(130, 200);
    h= random(400, 500);
    d= random(130, 200);

    noStroke();

    pessoa = createShape(BOX, w, h, d);
    pessoa.setTexture(img);
  }

  void render() {
    pushMatrix();
    rotateY(theta);
    translate(x, y-h/2, z);
    shape(pessoa);
    //box(w, h, d);
    popMatrix();
  }
}