Sky: Children of the Light, compressed vertice/uv positions in mesh file

[eblansson]

I've been looking into sky cotl's ".mesh" format and stumbled into a wall.

The mesh structure is known, you can read the amount of vertices and flags,
but I cannot manage to extract vertices and uvs.

The vertices and uvs are "zipped" or compressed somehow, and I cannot read or decompress them with anything.
Such files have a flag in the name "ZipPos", and another inside the file that determine whether those are compressed or not ("skipMeshPos, skipUv").
The flag is an integer with a value of exactly 4 times the vertice count. 

There are also some meshes where the vertices are not compressed and are perfectly readable.
In this case, the vertices take up 16 times the vertice count.

One possible lead that I got is that the game uses the orge-next engine, but I am not sure how is it relevant for this example.

I added an example of both occurences, and also a .hexpat file for ImHex. If I'm late to the party with this format, please let me know.

sky.zip

Edited November 25, 2023 by eblansson
link

[ptg1121]

I also use ImHex which is pretty good, close to 010Edit！