Add a fire map and trans to a swuished box or plane in poser. Make morph targets for it using magnets. Save to library. Load two into the scene and ciss-cross them so that from above the look like a cross. Put some logs around it and morph for effect, but make the motions quick and violent. Using multiple maps or just a different trans map helps. Smoke is done the same way but without crossing the planes. Just overlay about twenty planes and have them slide through each other as they go upward and spread outwards.