I am making a voxel-based game, and for needs of it, i am creating a block rendering engine.

Point is, that i need to generate lots of cubes. Every time i render more than 16x16x16 chunk of theese blocks, my FPS is dropped down hardly, because it renders all 6 faces of all of theese cubes. THat's 24 576 quads, and i dont want that.

So, my question is, How to stop rendering vertices(or quads) that are not visible, and therefore increase performance of my game?

Here is class for rendering of a block:

public void renderBlock(int posx, int posy, int posz) {
  try{
    //t.bind();
    glEnable(GL_CULL_FACE);
    glCullFace(GL_BACK);// or even GL_FRONT_AND_BACK */);

    glPushMatrix();

    GL11.glTranslatef((2*posx+0.5f),(2*posy+0.5f),(2*posz+0.5f));             // Move Right 1.5 Units And Into The Screen 6.0
    GL11.glRotatef(rquad,1.0f,1.0f,1.0f);

    glBegin(GL_QUADS);               // Draw A Quad

    GL11.glColor3f(0.5f, 0.4f, 0.4f);             // Set The Color To Green
    GL11.glTexCoord2f(0,0);
    GL11.glVertex3f( 1f, 1f,-1f);         // Top Right Of The Quad (Top)
    GL11.glTexCoord2f(1,0);
    GL11.glVertex3f(-1f, 1f,-1f);         // Top Left Of The Quad (Top)
    GL11.glTexCoord2f(1,1);
    GL11.glVertex3f(-1f, 1f, 1f);         // Bottom Left Of The Quad (Top)
    GL11.glTexCoord2f(0,1);
    GL11.glVertex3f( 1f, 1f, 1f);         // Bottom Right Of The Quad (Top)

    //GL11.glColor3f(1.2f,0.5f,0.9f);             // Set The Color To Orange
    GL11.glTexCoord2f(0,0);
    GL11.glVertex3f( 1f,-1f, 1f);         // Top Right Of The Quad (Bottom)
    GL11.glTexCoord2f(0,1);
    GL11.glVertex3f(-1f,-1f, 1f);         // Top Left Of The Quad (Bottom)
    GL11.glTexCoord2f(1,1);
    GL11.glVertex3f(-1f,-1f,-1f);         // Bottom Left Of The Quad (Bottom)
    GL11.glTexCoord2f(1,0);
    GL11.glVertex3f( 1f,-1f,-1f);         // Bottom Right Of The Quad (Bottom)

    //GL11.glColor3f(1.0f,0.0f,0.0f);             // Set The Color To Red
    GL11.glTexCoord2f(0,0);
    GL11.glVertex3f( 1f, 1f, 1f);         // Top Right Of The Quad (Front)
    GL11.glTexCoord2f(1,0);
    GL11.glVertex3f(-1f, 1f, 1f);         // Top Left Of The Quad (Front)
    GL11.glTexCoord2f(1,1);
    GL11.glVertex3f(-1f,-1f, 1f);         // Bottom Left Of The Quad (Front)
    GL11.glTexCoord2f(0,1);
    GL11.glVertex3f( 1f,-1f, 1f);         // Bottom Right Of The Quad (Front)

    //GL11.glColor3f(1f,0.5f,0.0f);             // Set The Color To Yellow
    GL11.glTexCoord2f(0,0);
    GL11.glVertex3f( 1f,-1f,-1f);         // Bottom Left Of The Quad (Back)
    GL11.glTexCoord2f(1,0);
    GL11.glVertex3f(-1f,-1f,-1f);         // Bottom Right Of The Quad (Back)
    GL11.glTexCoord2f(1,1);
    GL11.glVertex3f(-1f, 1f,-1f);         // Top Right Of The Quad (Back)
    GL11.glTexCoord2f(0,1);
    GL11.glVertex3f( 1f, 1f,-1f);         // Top Left Of The Quad (Back)

    //GL11.glColor3f(0.0f,0.0f,0.3f);             // Set The Color To Blue
    GL11.glTexCoord2f(0,1);
    GL11.glVertex3f(-1f, 1f, 1f);         // Top Right Of The Quad (Left)
    GL11.glTexCoord2f(1,1);
    GL11.glVertex3f(-1f, 1f,-1f);         // Top Left Of The Quad (Left)
    GL11.glTexCoord2f(1,0);
    GL11.glVertex3f(-1f,-1f,-1f);         // Bottom Left Of The Quad (Left)
    GL11.glTexCoord2f(0,0);
    GL11.glVertex3f(-1f,-1f, 1f);         // Bottom Right Of The Quad (Left)

    //GL11.glColor3f(0.5f,0.0f,0.5f);             // Set The Color To Violet
    GL11.glTexCoord2f(0,0);
    GL11.glVertex3f( 1f, 1f,-1f);         // Top Right Of The Quad (Right)
    GL11.glTexCoord2f(1,0);
    GL11.glVertex3f( 1f, 1f, 1f);         // Top Left Of The Quad (Right)
    GL11.glTexCoord2f(1,1);
    GL11.glVertex3f( 1f,-1f, 1f);         // Bottom Left Of The Quad (Right)
    GL11.glTexCoord2f(0,1);
    GL11.glVertex3f( 1f,-1f,-1f);         // Bottom Right Of The Quad (Right)

    //rquad+=0.0001f;
    glEnd();
    glPopMatrix();
  }catch(NullPointerException t){t.printStackTrace(); System.out.println("rendering block failed");}
}

Here is code that renders them:

private void render() {
  GL11.glClear(GL11.GL_COLOR_BUFFER_BIT|GL11.GL_DEPTH_BUFFER_BIT);
  for(int y=0; y<32; y++){
    for(int x=0; x<16; x++){
      for(int z=0; z<16; z++) {
        b.renderBlock(x, y, z);

      }
    }
  }
}