for (int i = 0; i < axiom.length(); i++) {
            char c = axiom.charAt(i);

            Matrix4f tempRotation = new Matrix4f();
            tempRotation.setIdentity();

            switch (c) {
                case 'G':
                case 'F':
                    // Tree trunk
                    view.setBlock(posX + (int) position.x + 1, posY + (int) position.y, posZ + (int) position.z, barkType, view.getBlock(posX + (int) position.x + 1, posY + (int) position.y, posZ + (int) position.z));
                    view.setBlock(posX + (int) position.x - 1, posY + (int) position.y, posZ + (int) position.z, barkType, view.getBlock(posX + (int) position.x - 1, posY + (int) position.y, posZ + (int) position.z));
                    view.setBlock(posX + (int) position.x, posY + (int) position.y, posZ + (int) position.z + 1, barkType, view.getBlock(posX + (int) position.x, posY + (int) position.y, posZ + (int) position.z + 1));
                    view.setBlock(posX + (int) position.x, posY + (int) position.y, posZ + (int) position.z - 1, barkType, view.getBlock(posX + (int) position.x, posY + (int) position.y, posZ + (int) position.z - 1));

                    // Generate leaves
                    if (_stackOrientation.size() > 1) {
                        int size = 1;

                        for (int x = -size; x <= size; x++) {
                            for (int y = -size; y <= size; y++) {
                                for (int z = -size; z <= size; z++) {
                                    if (Math.abs(x) == size && Math.abs(y) == size && Math.abs(z) == size)
                                        continue;

                                    view.setBlock(posX + (int) position.x + x + 1, posY + (int) position.y + y, posZ + z + (int) position.z, leafType, air);
                                    view.setBlock(posX + (int) position.x + x - 1, posY + (int) position.y + y, posZ + z + (int) position.z, leafType, air);
                                    view.setBlock(posX + (int) position.x + x, posY + (int) position.y + y, posZ + z + (int) position.z + 1, leafType, air);
                                    view.setBlock(posX + (int) position.x + x, posY + (int) position.y + y, posZ + z + (int) position.z - 1, leafType, air);
                                }
                            }
                        }
                    }

                    Vector3f dir = new Vector3f(1, 0, 0);
                    rotation.transform(dir);

                    position.add(dir);
                    break;
                case '[':
                    _stackOrientation.push(new Matrix4f(rotation));
                    _stackPosition.push(new Vector3f(position));
                    break;
                case ']':
                    rotation = _stackOrientation.pop();
                    position = _stackPosition.pop();
                    break;
                case '+':
                    tempRotation.setIdentity();
                    tempRotation.setRotation(new AxisAngle4f(new Vector3f(0, 0, 1), (float) Math.toRadians(angleInDegree + angleOffset)));
                    rotation.mul(tempRotation);
                    break;
                case '-':
                    tempRotation.setIdentity();
                    tempRotation.setRotation(new AxisAngle4f(new Vector3f(0, 0, -1), (float) Math.toRadians(angleInDegree + angleOffset)));
                    rotation.mul(tempRotation);
                    break;
                case '&':
                    tempRotation.setIdentity();
                    tempRotation.setRotation(new AxisAngle4f(new Vector3f(0, 1, 0), (float) Math.toRadians(angleInDegree + angleOffset)));
                    rotation.mul(tempRotation);
                    break;
                case '^':
                    tempRotation.setIdentity();
                    tempRotation.setRotation(new AxisAngle4f(new Vector3f(0, -1, 0), (float) Math.toRadians(angleInDegree + angleOffset)));
                    rotation.mul(tempRotation);
                    break;
                case '*':
                    tempRotation.setIdentity();
                    tempRotation.setRotation(new AxisAngle4f(new Vector3f(1, 0, 0), (float) Math.toRadians(angleInDegree)));
                    rotation.mul(tempRotation);
                    break;
                case '/':
                    tempRotation.setIdentity();
                    tempRotation.setRotation(new AxisAngle4f(new Vector3f(-1, 0, 0), (float) Math.toRadians(angleInDegree)));
                    rotation.mul(tempRotation);
                    break;
            }
        }