code: public Matrix3d sub(Matrix3dc subtrahend, Matrix3d dest) {
          dest.m00 = m00 - subtrahend.m00();
          dest.m01 = m01 - subtrahend.m01();
          dest.m02 = m02 - subtrahend.m02();
          dest.m10 = m10 - subtrahend.m10();
          dest.m11 = m11 - subtrahend.m11();
          dest.m12 = m12 - subtrahend.m12();
          dest.m20 = m20 - subtrahend.m20();
          dest.m21 = m21 - subtrahend.m21();
          dest.m22 = m22 - subtrahend.m22();
          return dest;
      }
docs: /* (non-Javadoc)
  @see org.joml.Matrix3dc#sub(org.joml.Matrix3dc, org.joml.Matrix3d)