Game engines... like UE4, just pay $20 and then cancel the subscription plan, you will still be able to use UE4. Theres Cryengine, I think free, and also Unity. Also apparently Quixel will have a prb viewer for free but I could be wrong on that. The power of marmoset though is not just the quality, but also the convenience…
AFAIK not much has been said about Quixel's previewer but given the quality of their other products, my guess is that it will be pretty great. It comes bundled with the Quixel Suite which seems like it will be an amazing use of $100. Other than that, game engines will probably be your best bet. It's not all bad though, the…