Mandelbulb 3D Monte Carlo Renderer:
The Complete Guide
Physically-based light for your fractals — when to use it, how to survive the render times, and the official speed tricks nobody collected in one place.
Quick Answer: The M.C. renderer is MB3D’s path tracer: realistic global illumination at up to 100× the render time of the standard renderer. Use the standard renderer for exploration, switch to M.C. for hero frames. You can stop and resume M.C. renders anytime, and since sr37 it supports Z-buffer output.
When M.C. Is Worth It
Monte Carlo earns its cost on scenes with complex light interaction: interiors of fractal structures, translucent materials, soft realistic shadows, and subtle bounced light. For flat illustrative styles or quick iterations, the standard renderer is the right tool — don’t pay the 100× tax for looks the standard engine already nails.
Official Speed Tricks (from the Maintainers)
Preview in the standard renderer first
Dial in composition, lighting direction, and materials with the fast default renderer — then Send parameter to main to carry settings into the M.C. renderer. Never explore in M.C. mode.
Raise the raystep multiplier
Increase it until the first overstepping artifacts appear, then back off slightly — minor overstepping is invisible in the final image but each step saved is time earned.
Kill useless lights & tame shadows
Hard shadows are always calculated — switch off any light contributing little, and prefer positional lights for interiors. To disable hard-shadow calculation entirely, reduce max length calc to 0. Use MaxL in the postprocess DEAO settings to cap ambient ray length.
Keep dIFS iterations minimal
With dIFS formulas the engine always computes up to the maximum iteration count — set it as low as the structure allows. Ambient and reflection ray depth also scale cost directly; lower values render faster at some realism cost.
Stop, resume, and batch
M.C. renders can be stopped and continued later without losing samples. Save the .m3c file to enable automatic file storing, and use the M.C. batch render module (with sr36+ network rendering) to queue sequences overnight. Gamma, contrast, and soft clipping stay adjustable at any time — the maintainers recommend internal gamma 2 (‘I2’ in the lighting tab).
Watch out: dynamic fog can destroy realism (e.g. when light is subtracted), and not all caustics are implemented — light behind transparent objects isn’t accurate. Know the limits before promising a client photorealism.
Frequently Asked Questions
What is the Monte Carlo renderer in Mandelbulb 3D?
A path-tracing renderer that simulates realistic global illumination — bounced light, soft shadows, and physically plausible materials — at up to 100× the render time of the standard renderer.
Can I pause and resume a Monte Carlo render?
Yes — stop the calculation anytime and continue later; accumulated samples are kept. Save the .m3c file to enable automatic file storing across sessions.
Does the M.C. renderer support Z-buffer output?
Yes, since V1.99.37 — enable “With ZBuffer” and the depth pass saves alongside the image, including in M.C. batch render and network rendering (enable it on all nodes).
Why is my M.C. render taking forever?
Path tracing converges slowly by nature. Apply the speed tricks above — especially killing useless lights, minimal dIFS iterations, and the raystep multiplier — and reserve M.C. for final hero frames only. See our render speed guide for the general rules.