1. Input Textures: The tool allows the user to specify four input textures:Diffuse Map: Represents the color information of the material.
   Normal Map: Contains surface normals for simulating bumps and crevices.
   Metallic Map: Defines the material's metallic properties.
   Ambient Occlusion Map: Encodes ambient occlusion information for shading.
   
2. User Interface: The tool provides a user-friendly interface within Unity's editor. Users can input a desired "Texture Name" and select the four input maps using object fields.
3. Generate Mask Map: Upon clicking the "Generate Mask Map" button, the tool checks if all input maps are provided and have the same dimensions. If any criteria are not met, error messages are displayed.
4. Mask Map Generation: If input maps are valid, the tool proceeds to generate the Mask Map. It creates a new Texture2D with the same dimensions as the input maps. For each pixel in the maps, it extracts specific information:Metallic Value: Extracted from the red channel of the Metallic Map.
   Ambient Occlusion Value: Extracted from the green channel of the Ambient Occlusion Map.
   Smoothness Value: Calculated based on the Normal Map.
   These values are combined to create the Mask Map pixel color.
5. Saving the Mask Map: After generating the Mask Map successfully, the user can click the "Save Mask Map" button. The tool allows the user to specify a folder for saving the Mask Map as a PNG file. If a file with the same name already exists, the tool prompts the user to confirm whether they want to overwrite it.
6. File Management: The tool checks if the target folder exists and creates it if not. It then encodes the Mask Map as a PNG image and saves it to the specified path. The saved file is immediately recognized by Unity through AssetDatabase.Refresh().
7. Feedback: The tool provides feedback to the user through the Unity console, indicating whether the Mask Map generation and saving processes were successful or if any errors occurred.

In summary, this Unity tool streamlines the process of generating a Mask Map, which is crucial for realistic material rendering in 3D environments. It offers a convenient user interface for inputting textures, generates the Mask Map based on specific rules, and allows users to save the resulting Mask Map for use in their Unity projects.