public void bezier(float x1, float y1, float z1,
                     float x2, float y2, float z2,
                     float x3, float y3, float z3,
                     float x4, float y4, float z4) {
    beginShape();
    vertex(x1, y1, z1);
    bezierVertex(x2, y2, z2,
                 x3, y3, z3,
                 x4, y4, z4);
    endShape();
  }