I wasn't aware that OpenOffice is the gold standard w.r.t. ODF rendering, or even that having such a standard makes sense. I would think that, if you want to ensure your document renders the same everywhere, the right approach is to create a .pdf or .png document.

If there is really a need for perfect rendering of ODF documents, the best approach is probably to compile the relevant part of OpenOffice. Writing a 100% complete ODF implementation from scratch is very hard.