.M3I Image + ParameterEdit
The .M3I Image + Parameter file is the native file format of Mandelbulb3D. It can store the rendered Image (before or after Postprocessing), fractal parameters found in the Formulas window, lighting and shading data in the Lighting window, and program settings in the Main Window.
.M3I is a binary format and cannot be read or edited by humans.
When a .M3I file is saved from the Save tab in the Main Window, the image and all scene parameters are stored. If the Image checkbox is on, then the final image, including all Postprocess options, is stored in the .M3I file. If it's off, Postprocess results in the frame buffer aren't saved.
When a .M3I file is saved from the Lighting window, only the lighting and shading information is stored. This enables users to store lighting and shading independently of the fractal formula parameters, and to create lighting and shading presets.