MFFS uses a DirectoryLister sprite source to add the textures for its blocks with detailed models to the block atlas. The default DirectorySource is not namespaced, which means that any texture in the specified directory or subdirectory thereof gets added, regardless of the texture's namespace. Since the textures/models/ directory is often used for large texture maps used by "entity" models which are rendered by entity renderers or BERs and which are not intended to be stitched to an atlas, this causes the block atlas to be bloated by these unnecessary textures. In 1.21.1 this can be fixed by using the NamespacedDirectoryLister provided by NeoForge since 21.1.29 instead. In earlier versions, this custom sprite source needs to either be implemented manually or the individual textures added by a SingleFile sprite source per texture.

Versions

NeoForge: 21.1.54
MFFS: 5.4.6

Steps to Reproduce

1. Install MFFS together with a mod that adds its own textures in textures/models/ (i.e. Iron Chests)
2. Inspect the block atlas with vanilla's atlas dump keybind (F3 + S) or AtlasViewer (the latter includes information about which resource pack contains the sprite source adding a given texture)