Install

1. Download the zip (do not unzip it).
2. Edit → Preferences → Get Extensions → small arrow menu at the top right → Install from Disk → pick the zip.
3. Press N in the 3D viewport and open the Image Per Instance tab.

Quick start

1. Choose your Image Folder, pick a Tile Size and Padding, and set Order (By file name or Shuffle). Press Build Atlas.
2. Separate objects: select the meshes and press Apply To Selected Objects. Every object gets its own image through one shared material.
3. Geometry Nodes instances or arrays: make the object that carries the Instance on Points / Array modifier the active object and press Add To Instances (Geometry Nodes). The add-on finds the instanced source objects, gives them the shared material and adds a small modifier that stores an image index per instance.
4. Shuffle: set Order to Shuffle and a Seed. Change the Seed and press the apply button again for a different arrangement.

Notes

• Your objects need UVs that fill the 0-1 square. A plane or an unwrapped cover works.
• All images are packed to square tiles of the chosen size. The atlas is stored inside the .blend; there are no external files.
• Only material slot 1 of the source object is replaced.
• Building the atlas again replaces the old one. Ctrl+Z (Cmd+Z on Mac) undoes any step.
• The folder must contain image files (png, jpg, ...). An empty folder gives a clear error message.