didnt open the window to set name

[Unneeded8793]

when i press button to save atlast didnt open the window to set name and write duplicate as notify output

[Grim-es]

When using materials with the same image in their Image Texture node, the materials will merge instead of being atlased. Or, if the proper image is not found, they will default to the color property, which, if the same, will also merge materials. To ensure proper functionality, make sure the shader you're using is listed in the supported shaders in utils/materials.py, and that the name property is in English and matches exactly as listed in that file.

The easiest will be using the Diffuse BSDF shader with a name property set to Diffuse BSDF. Then, directly connect the image intended for the atlas to the shader using an Image Texture node with its name property set to Image Texture. To verify the name property of nodes, select the node and press the 'N' key on keyboard to open a small right-side panel displaying that data.

Note that simply changing Blender to English will not automatically rename already imported or saved nodes. It will be necessary to manually rename them or reimport the model from the beginning.

So, combined materials either use the same texture (which you can export by pressing File > External Data > Unpack files to current directory), or have the name property and shader not match the pre-hardcoded listed ones, and their texture is not used in the atlasing process.