You can make a skybox directly in godot.
Make a new environment in your camera inspector and set cubemap for background mode. Than make a new cubemap and load images.
Note that the question is not “How to make a cubemap in godot”, but is “How to use cubemap exported from blender directly in godot”, since godot wants 6 images for the cube, while blender would arrange them in a 3x2 square.
Bojidar Marinov | 2016-03-23 09:13
Ah, sorry! I should read better.
del | 2016-03-23 20:01
As of v. 3.5.1 (Nov. 2022), cubemap is no longer an option for background mode, alas.
It is now. In fact, as of the current version (as of this writing, v. 3.5.1), you can’t use a cubemap or a six-sided image since this is no longer a Background option in WorldEnvironment: it must be an equirectangular panorama image, so you have to use a converter. Experimentation has shown me that a panorama image sized 1280 x 720 works well for 3D environments. Each of your six source faces should be 1024 x 1024 (if you’re starting from a cubemap).