My opinion as an author:  An artist or author has automatic copyright on the work they produce, which means you cannot copy and sell the work. However, there is nothing to prevent you taking inspiration from that work and using it produce your own, especially as you are using a different media, Bryce rather than paints.

Additionally, if you only want to post it on the forums, you are not making money selling, so there really is no problem. You could credit the artist in a note with the picture if you feel the original work deserves a mention. Is the artist still living? I don't recognize the name.

 

Rob.

---

As a writer, I control the lives of millions. Whole worlds can be destroyed by typing the correct sequence of letters on my keyboard.

Robert A. Read