Why are input textures not merged into a single output texture?

There are several reasons why TexturePacker3D may not be able to pack all input textures of a given type into one output texture:

• Textures are too large: The combined textures exceed the maximum output texture size. To resolve this, either increase the maximum texture size or scale down the input textures before importing them into TexturePacker3D.

• Unpackable textures: A texture may be classified as "unpackable" if its UV coordinates extend beyond the [0,1] range. For more details, see this article.

• Different channel usage: If your models use different combinations of texture channels — for example, one uses Albedo + Normal, and another one uses Albedo + Emissive — they might not be packed together. This is because mixing them would result in wasted space in channels not used by all textures (e.g., an empty emissive channel for a model that only uses Albedo + Normal).

• Other packing restrictions: Additional constraints might prevent merging. TexturePacker3D will display additional information in the dialog that appears when you click "Run Packer".