Base Matter

Base Matter is a fully 3D material simulation sandbox built around experimentation, machinery, and interacting systems. Build structures, machines, pressure vessels, fluid systems, reactors, and whatever else you can come up with using a volumetric grid of simulated materials. Then start the simulation and see what happens. Sand falls and piles up. Liquids flow and separate. Heat spreads through materials. Water freezes, boils, and condenses. Fuel needs oxygen to burn. Pressure builds inside sealed spaces and can rupture weaker materials. Salt dissolves into water. Plants consume resources and grow. Acid corrodes. Gunpowder chains. Machinery moves matter around the world. Base Matter is designed as an open-ended sandbox. There are no missions, progression systems, or prescribed objectives. Build an experiment, run it, inspect the results, change something, and try again. Build functional systems Use pumps, valves, heaters, coolers, filters, fans, gas pumps, pistons, pushers, timers, sensors, switches, logic gates, sources, drains, and other devices to create working machines and automated experiments. Recent builds also include basic nuclear reactor materials, including uranium, neutrons, control rods, copper heat conductors, and reactor steel. Look inside your experiments Base Matter is not just about watching things happen from the outside. Switch between normal 3D editing, thin slice editing, and cutaway views to work inside complex builds. Use matter, heat, pressure, and power display modes to understand what the simulation is doing, and place probes to track values over time. Experiment without losing your work Pause the simulation, advance one tick at a time, save worlds, copy machines as reusable stamps, create checkpoints, and use limited rewind history to inspect or recover experiments. Current features - Fully 3D voxel-based material simulation - Powders, liquids, gases, solids, fire, steam, molten materials, and more - Heat transfer and phase changes - Combustion and oxygen-dependent burning - Pressure and sealed chambers - Corrosion, explosions, growth, moisture, salinity, and material storage - Electrical logic and automation - Pumps, valves, filters, pistons, fans, heaters, coolers, and other machinery - Nuclear reactor materials - Slice editing and cutaway viewing - Heat, pressure, power, and matter visualization - Probes and graph history - Saves, autosaves, stamps, checkpoints, undo, and rewind - Built-in example scenes - Large worlds supporting roughly one million available cells Early alpha Base Matter is currently in active development. Systems may change, bugs are expected, and performance can vary significantly depending on world size and how much of the simulation is active. The simulation is intentionally simplified and is designed for experimentation rather than scientific or engineering analysis. If you build something interesting, strange, useful, or catastrophic, I want to see it. Build it. Run it. See what happens.