Mandelbulb 3D File Formats:
M3P, M3I, M3F, M3A Explained
Downloaded a parameter pack and don’t know what to do with it? Every MB3D file type explained: what it holds, how to open it, and which one to share.
Quick Answer: .m3p = parameters only (share this), .m3i = parameters + rendered image, .m3f = formula definition, .m3a = animation data, .mc3 = Monte Carlo render data. Open them from the Open tab on MB3D’s main window — or drag & drop the file onto the program.
.m3p — Parameters SHARE THIS
The community’s currency. Stores formulas, lighting, and postprocess settings — everything needed to recreate the scene, but no image data. Compressed binary, tiny files. This is what parameter packs on FractalForums contain. Save your scene as default.m3p in the program folder to load it automatically on startup.
.m3i — Image + Parameters
The native working file: stores the rendered image (always full-size, regardless of view zoom) together with all parameters and light settings. If Img is checked, reflections and depth-of-field are included too. Use it to archive finished work or resume a scene exactly where you left it.
.m3f — Formula
A single formula definition — the mathematical DNA of a fractal shape. Readable and editable as text, though the formula core itself is machine code. The stock library lives in the M3Formulas folder; community formulas install by dropping .m3f files there.
.m3a — Animation
Animation Maker data: keyframes, camera paths, and per-frame parameter changes. Compressed binary. Pairs with the matching .m3p — together they fully describe an animation project. See Cinematic Motion.
.mc3 — Monte Carlo Data
Path-tracer state for the M.C. renderer. Lets you pause and resume long Monte Carlo renders without losing accumulated light samples.
Three Ways to Load Parameters
1. Open tab — Main window → Open tab → pick the file. The classic route.
2. Drag & drop — since V1.8, drop .m3p/.m3i files (or PNGs with embedded parameters) directly onto the main window.
3. Clipboard text — copy parameter text, hit the TXT load button; save back out with the TXT save button. Perfect for forum posts.
Lost work? MB3D auto-saves a history: every time you press Calculate 3D, the parameters are written as .m3p into the History subfolder, organized by date and time. Browse it to recover any earlier state of your scene.
Frequently Asked Questions
What program opens .m3p files?
Only Mandelbulb 3D itself — .m3p is its proprietary parameter format. Download MB3D free, then load the file from the Open tab or drag & drop it onto the main window.
Can I edit .m3p files in a text editor?
No — .m3p is compressed binary. To share parameters as text, use the TXT clipboard buttons: they export the same data in copy-pasteable text form.
What’s the difference between .m3p and .m3i?
.m3p stores parameters only (tiny, ideal for sharing); .m3i stores parameters plus the rendered image (larger, ideal for archiving finished work and resuming scenes).
Where do I put downloaded .m3f formula files?
Copy them into the M3Formulas folder inside your MB3D installation — they appear in the formula list the next time you open the Formulas window.