Hello there!
I imported my 4k DDS cubemap (6*4K). It takes a long time to import, circa 20/30 min. ([Known issue][1] ). It takes that long because it is generating mipmaps which destroys the quality of the cubemao.
With the mipmaps on:
Mipmaps turned of:
Cubemap without mipmaps:
Cubemap in material instance editor after mips are turned of:
Cubemap material editor. NOTE: The preview looks beautifull:
Then i have the original file. and the export settings. I will show them in a post below (due to file limit in post)