Procedural nebulae formations produced using FilterForge. Rendered results were processed using Photoshop. Originally, this project was intended to be used as part of a game. The art direction in the game later changed but I continued the development of it.

Below: the details of the nebulae at 100%. Note that the generator is resolution independent.

The filter itself is relatively complicated. There are tons of parameters to tweak. Specific items can be exported out as separate layers: Stars, nebulae color, nebulae cloud, the overall apperance, and apperance with all the post-effects (color grading and glows).