Sandustry Falling Sand Physics – Design Around Moving Pixels
Learn Sandustry falling sand physics through gravity-safe routing, fluid separation, temperature zones, blockage tests, and observable factory geometry.
Published 2026-08-21 · Updated 2026-08-21 · Early Access guidance
Understand the design constraint
Sandustry simulates individual material pixels with their own properties. The official materials specifically describe sand, snow, seeds, spores, ice, water, steam, heating, rain, and physical reactions. A factory is therefore geometry plus machinery. Nominal transport capacity means little if material arches over an opening, settles outside the capture area, or changes state before reaching its destination. Build to observe these behaviors instead of assuming a clean item-belt abstraction.
Use gravity deliberately
Prefer routes where the desired material naturally falls toward its next capture point and unwanted material cannot fall into the same opening. Avoid hidden horizontal shelves where a few pixels can accumulate. Widen transitions before narrowing them, and leave access below tall drops. When a chute fails, inspect the lowest obstruction first. Removing support above a blockage can release a large mass, so isolate input and provide empty capacity beneath before digging.
Control fluid levels with geometry
Water seeks available space and can occupy the route intended for sand. Set a visible operating line, position drains and outputs relative to that line, and test both empty and full states. Steam rises, while the official description says it can return as rain if allowed to reach the sky; do not assume that guarantees lossless recovery in every layout. Keep steam tests separate from the main reservoir until the complete cycle has survived travel, pause, and reload.
Separate temperature experiments
Ice, water, steam, fire, and heated materials can affect neighboring pixels. Use insulation distance and isolated test chambers for new reactions. Start with a minimal sample and document the starting and ending materials. Do not infer exact conversion ratios from visual bursts. Community posts can reveal candidate interactions, but only repeatable observation in the current build should control a production design. Provide a non-destructive way to remove heat or divert output.
Design for moving boundaries
A pile changes shape as material enters and leaves. An outlet that works when empty may be covered when full, while an inlet above a low pool may become submerged. Test the complete operating range rather than one screenshot state. Mark maximum pile and fluid lines. Add a separate sensor-by-observation pocket if the active chamber is hard to read. The best compact design is one whose critical boundaries remain visible.
Use the sandbox checklist
Before integrating a layout, reproduce its core geometry in the local sandbox notebook. Test normal flow, no input, no output, excess fluid, excess solid, and save/reload. Record what the test proves and what it does not. The browser sandbox on this site does not simulate the game engine; it is a planning grid for marking zones and hazards. In-game verification remains required, particularly after Early Access patches.
Sources and evidence notes
- Sandustry on Steam
Tier 1. Developer/publisher description, Early Access status, features, and requirements; checked 2026-08-21.
- Sandustry by Lantto
Tier 1. Developer overview of falling sand, automation, exploration, bosses, puzzles, and tech; demo-era mechanics are not treated as retail balance facts.
- r/SandustryGame community
Tier 4. Used for demand signals and candidate failure modes; ratios and workarounds require in-game verification.