Remapping Hallownest seems pretty easy at first sight – just take some screenshots and stitch them together, however this is very far from the reality of it.
This is part 1 of demonstrating the mapping process: screenshotting, piecing the screenshots together, using layer masks and touching up each room.
It is important to note that Hollow Knight, despite being played in 2D, is a game built in 3D and it uses parallax scrolling, therefore as you move left and right or up and down, certain things will shift position, resulting in a ton of seams and mismatching back- and foreground objects, depending on the room.
This is usually not an issue with most rooms but with very long vertical rooms, it makes my life really really hard, especially if the room has a structure where it is important that things align for example hanging chains and straight walls or some huge detailed thing in the background.
The process is gradual – first I work on rooms individually. I open up a big canvas, I drag in all the screenshots I’ve taken in that room, take some extra time aligning the screenshots so certain objects match up such as a statue, a platform or a Geo node as a point of reference, sometimes I use more than one screenshot of the same thing just in case.
At this point, I start adding layer masks and start drawing on them, blocking out unneeded parts. Technically, this is almost the same as using the eraser, except I can easily undo my changes. Once the masking process is done, the whole thing looks almost alright.
Marked with yellow are the mistakes and areas that need some touch-up or fixing. These include messy seams, misaligned objects, lighting issues and semi-transparent anomalies. Sometimes I need to mask out enemies if they are in an unfavourable position or frame and redo them from the sprite sheets.
After this I spend some time touching up these areas and checking for mistakes. The best way to do this is blowing up the contrast and brightness with a filter so I can see the problems easier.
The room is now finished. Now onto the rest of the rooms until all rooms of the area in question are done to this point.