In this tutorial, I will show you how to quickly make a skybox for use in a game engine using Affinity Photo.
Sky box
The photo I am using is from Pexels
Use a 2:1 image so it will appear seamless when used on a dome shape
In my case, I will use a 3840 x 1920 scale
Unlock the layer
Duplicate the image and flip it horizontally
Select the duplicated layer and add a mask
Use the gradient tool and add a small gradient from one of the sides
Merge the layers
Make another duplicate
Hide the bottom layer
Select the top layer and under the Filters menu, go to Distort and then Rectangular to Polar
Using a soft brush, select the Healing Tool
Hold down ALT and Left-click to select an area and then use Left-click to paste the selected area
I would recommend trying a hardness of 25-percent but you may need to adjust this number
To unwrap the image, go to Filters, and under Distort, use Polar to Rectangular
For the ground, if you want the same type of image as the sky – that is a mirrored image, rotate the layer vertically
Then repeat the process with the Polar Coordinates
Rotate the image vertically so the land is back in place
If you want to use this image for lighting, you need to go to Document and Convert Format/ICC Profile
Change the Format to RGB/32 (HDR)
Export the image as an EXR (which can be used by Unreal Engine, Unity, and Godot)