LibGdx ModelBuilder box with faces seperated

PlaneModelFactory.java

import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.VertexAttributes;
import com.badlogic.gdx.graphics.g3d.Material;
import com.badlogic.gdx.graphics.g3d.Model;
import com.badlogic.gdx.graphics.g3d.attributes.ColorAttribute;
import com.badlogic.gdx.graphics.g3d.utils.ModelBuilder;

/**
 * Used to render boxes with their faces seperated.
 */
public class PlaneModelFactory {
  /**
   * Create a box with faces seperated.
   *
   * @return The model to create instances from.
   */
  public Model create(){
    ModelBuilder modelBuilder = new ModelBuilder();
    return box(modelBuilder, 1, 0.25f, 1);
  }

  /**
   * creates the box's faces. modelBuilder.begin() must be called first. The result is then retreived by
   * modelBuilder.end().
   *
   * @param modelBuilder The modelBuilder to queue faces into.
   * @param w            The width of the box.
   * @param h            The height of the box.
   * @param v            The depth of the box.
   */
  private Model box(final ModelBuilder modelBuilder, final float w, final float h, final float v){
    final long attr = VertexAttributes.Usage.Position | VertexAttributes.Usage.Normal;
    // used because entering a plain 0 makes intellij render help labels in a parameter list
    final float o = 0;

    // @formatter:off

    //            _____________
    //   0,h,d ->/|     f     /|<- w,h,d
    //          /_|_____ ____/ |
    // 0,h,0 ->|  |     c    | |<- w,h,0
    //         | b|    d     |e|
    // 0,0,d ->|  |__________|_|<- w,0,d
    //         | /     a     | /
    // 0,0,0 ->|/____________|/<- w,0,0

    Model a = modelBuilder.createRect(
                    o, o, o,
                    w, o, o,
                    w, o, v,
                    o, o, v,
                  0, -1, 0,
                    new Material(ColorAttribute.createDiffuse(Color.MAGENTA)),
                    attr);

    Model b = modelBuilder.createRect(
                    o, o, o,
                  o, o, v,
                  o, h, v,
                  o, h, o,
                  -1, 0, 0,
                  new Material(ColorAttribute.createDiffuse(Color.MAGENTA)),
                  attr);

    Model c = modelBuilder.createRect(
                  o, o, v,
                  w, o, v,
                  w, h, v,
                  o, h, v,
                  0, 0, -1,
                  new Material(ColorAttribute.createDiffuse(Color.MAGENTA)),
                  attr);

    Model d = modelBuilder.createRect(
                  o, o, o,
                  o, h, o,
                  w, h, o,
                  w, o, o,
                  0, 0, 1,
                  new Material(ColorAttribute.createDiffuse(Color.MAGENTA)),
                  attr);

    Model e = modelBuilder.createRect(
                  w, o, o,
                  w, h, o,
                  w, h, v,
                  w, o, v,
                  1, 0, 0,
                  new Material(ColorAttribute.createDiffuse(Color.MAGENTA)),
                  attr);

    Model f = modelBuilder.createRect(
                  o, h, o,
                  o, h, v,
                  w, h, v,
                  w, h, o,
                  0, 1, 0,
                  new Material(ColorAttribute.createDiffuse(Color.MAGENTA)),
                  attr);

    modelBuilder.begin();
    modelBuilder.node("a", a);
    modelBuilder.node("b", b);
    modelBuilder.node("c", c);
    modelBuilder.node("d", d);
    modelBuilder.node("e", e);
    modelBuilder.node("f", f);
    return modelBuilder.end();
    // @formatter:off
  }
}