backgrounds in 3D environments or to create three-dimensional 

Gaussian Splatting-type worlds using tools such as Marble.

Suggested steps:

You can create a front and back image in your favorite drawing program.

You can upload the two images in their corresponding positions 

(you can upload just one or all six individual square images); the application will 

form the cubic maps into a seamless, high-resolution 360° projection (4096 x 2048 px).

After processing the images, you will see that the result is a single equirectangular

image. The missing images were filled with transparent space, but you can fill it

automatically to make it easier to continue coloring from that point. 

It also offers the ability to project images directly onto the 3D visualization with

extreme precision. But to do that, I recommend first taking a screenshot using the

button indicated and working directly on the screenshot.

Once done, we can upload the corrected result and adjust the image until it is in the

right place and project it at that moment. 

You can upload as many images as you  want to project them and make large collages. 

The app can also be used to view our illustrations in 360, since painting one of these

illustrations displayed in 2D causes us to lose perspective on sizes and distances, 

so it is useful to review the scene in 3D from time to time.

Finally, you can upload it to an app to create explorable three-dimensional scenes

such as Marble so that you can walk through your scene and convert it into a 3D

mesh scene.