A cubemap is made of 6 textures organized in layers. They are typically used for faking reflections in 3D rendering (see [ReflectionProbe]). It can be used to make an object look as if it's reflecting its surroundings. This usually delivers much better performance than other reflection methods.
This resource is typically used as a uniform in custom shaders. Few core Godot methods make use of [Cubemap] resources.
To create such a texture file yourself, reimport your image files using the Godot Editor import presets. The expected image order is X+, X-, Y+, Y-, Z+, Z- (in Godot's coordinate system, so Y+ is "up" and Z- is "forward"). You can use one of the following templates as a base:
[b]Note:[/b] Godot doesn't support using cubemaps in a [PanoramaSkyMaterial]. To use a cubemap as a skybox, convert the default [PanoramaSkyMaterial] to a [ShaderMaterial] using the [b]Convert to ShaderMaterial[/b] resource dropdown option, then replace its code with the following:
// If importing a cubemap from another engine, you may need to flip one of the `EYEDIR` components below
// by replacing it with `-EYEDIR`.
vec3 eyedir = vec3(EYEDIR.x, EYEDIR.y, EYEDIR.z);
COLOR = texture(source_panorama, eyedir).rgb * exposure;
}
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After replacing the shader code and saving, specify the imported Cubemap resource in the Shader Parameters section of the ShaderMaterial in the inspector.
Alternatively, you can use [url=https://danilw.github.io/GLSL-howto/cubemap_to_panorama_js/cubemap_to_panorama.html]this tool[/url] to convert a cubemap to an equirectangular sky map and use [PanoramaSkyMaterial] as usual.
