Update #4 Physics · Factory Retrofit
Update #4 (v0.5.7) patched the issue where liquids leaked horizontally through Advanced Filter Walls. While this hardened fluid containment, it fundamentally altered solid-to-fluid boundary interactions: solid materials pushed horizontally on conveyor belts into liquid columns now halt rather than penetrating. This guide details why horizontal wetting broke and provides field-tested launcher displacement and vertical gravity drop rebuilds.
Quick answer
Update #4 fixed a bug where liquids leaked through Filter Walls, which inadvertently stopped horizontal conveyor belts from pushing solids directly into standing water columns. To fix stalled production lines: replace horizontal belt feeds with downward vertical drop chutes (gravity easily penetrates fluid boundaries) or use Launchers to fire solids into the liquid.
01
In Update #4 (v0.5.7), the engine received vital hardening to eliminate a long-standing vulnerability: Lava and other fluids leaking horizontally through Advanced Filter Walls. While this fix successfully secured fluid pipelines, it introduced a significant side effect to falling-sand pixel mechanics.
Under the patched boundary rules, conveyor belts pushing solid items horizontally directly into adjacent liquid columns now halt at the liquid perimeter. The conveyor treats the fluid surface as an immovable boundary wall rather than a penetrable pool, creating immediate upstream backlog deadlocks in legacy wet seed and gold wetting factories.
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The physical distinction between conveyor feed and free fall is central to resolving this stall. Conveyor belts impart only horizontal kinetic translation, which the hardened fluid surface algorithm halts.
In contrast, free-falling solid pixels possess vertical momentum. When dropped from a gravity chute at least two tiles above the water line, items like raw Sand or dry Seeds plunge directly through the fluid surface, triggering instantaneous wetting reactions (producing Wet Sand and Wet Seeds) without stalling the incoming supply lines.
03
Where factory ceilings or compact layouts prevent high vertical drop chutes, Launchers provide the optimal engineering solution. As proven in community stress testing (u/ergzay), Launchers impart sufficient projectile velocity to overcome fluid surface resistance.
Firing solid Gold or Seeds from a Launcher directly into a contained water column forces the solids through the liquid barrier. Crucially, this interaction preserves the physical displacement mechanic: solid influx actively pushes liquid pixels upward, allowing buoyant Wet Seeds to float toward surface skimming vents while denser byproducts sink.
| Feeding Method | Update #4 Status | Recommended Retrofit |
|---|---|---|
| Horizontal Conveyor to Liquid | Stalled (Items stop at boundary) | Convert to 2+ tile vertical drop chute |
| Vertical Gravity Drop into Basin | Operational (Gravity penetrates surface) | Standardize overhead chutes with drop clearance |
| Launcher Injection into Fluid | Operational (Kinetic force displaces fluid) | Use Launchers for tight horizontal spaces |
| Filter Wall Horizontal Floor | Broken (Altered item throughput) | Replace with angled Shakers or Conveyor Portals |
| Advanced Filter Wall Liquid Seal | Fixed (Lava/Water no longer leak) | Safely isolate adjacent liquid and solid lines |
04
Engineers who utilized horizontal Filter Walls as floor grids to evenly distribute mixed inputs reported broken distribution lines after the update (u/NitroBishop). Because solid pass-through behavior was recalibrated, items can no longer be passively sieved across flat floor filters without jams.
The recommended retrofit is replacing passive filter floors with downward-slanted Shakers or alternating Conveyor Portals. Additionally, players can leverage the Advanced Filter Wall multi-element selection feature (u/SQLSpellSlinger) to configure multi-item allow-lists on vertical dividing walls, simplifying sorting manifolds without requiring nested filtering stages.
Questions answered
Update #4 (v0.5.7) hardened fluid containment rules to fix Filter Wall liquid leaks. As a side effect, horizontal conveyor belts can no longer push solid items into liquid columns, causing production deadlocks.
In Update #4 (v0.5.7), fluid boundary rules were hardened to prevent liquid leaks through Filter Walls. This change also blocks horizontal conveyor belts from sliding solid items directly into standing water columns. Replacing the horizontal belt with a downward vertical drop chute (letting items drop through the surface from above) or a Launcher resolves the stall immediately.
Use vertical gravity drops where items fall from above into water, or use a Launcher to propel items into the liquid column with kinetic velocity.
Yes. Solids fired into liquids via Launchers or dropped from height actively displace fluid pixels upward, allowing buoyant items like Wet Seeds to float while heavy items sink.
Replace horizontal filter floors with downward-angled Shakers or paired Conveyor Portals, which distribute solids without triggering fluid boundary locks.
Yes. In recent updates, players can configure Advanced Filter Walls to filter multiple selected elements simultaneously, simplifying sorting manifolds.
Evidence notes
These are useful player examples, not official specifications.
