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Generate Cellular Automata Cells

Generates organic cave-like regions using a cellular automata smoothing process.
Starts from random noise inside Bounds, then iteratively applies simple local rules to evolve walls and floors into natural shapes.

What it does

  1. Initializes a grid in Bounds where each cell starts as wall with probability Initial Wall Chance (otherwise floor).

  2. Repeats Iterations times:

    • Counts neighbors (4-way or 8-way) around each cell.
    • Applies two thresholds:
      • Wall Erode Threshold - walls with too few wall neighbors erode into floor.
      • Wall Regrow Threshold - floors with many wall neighbors regrow into wall.
    • Returns the final set of open/floor cells as Vector2Int positions.

This produces anything from blobby caverns to chunky, gridded tunnels depending on your neighbor mode and thresholds.

Inputs

Field Description
Bounds BoundsInt area to simulate (cell/grid coordinates).
Initial Wall Chance Probability each cell starts as wall. Lower → more open; higher → more solid. Typical range 0.45–0.65.
Use 8 Neighbors When true, use 8-way neighbor counts (rounder, more organic). When false, use 4-way (chunkier, more orthogonal).
Wall Erode Threshold Walls with fewer than this many wall neighbors erode to floor. Higher → walls erode more easily.
Wall Regrow Threshold Floors with at least this many wall neighbors regrow to wall. Higher → open space stays open.
Iterations Number of smoothing passes (1–6). Fewer = noisy; more = smoother (too many can collapse to all floor or all wall).

Outputs

Field Description
Cells All final floor cells as Vector2Int positions (optional).

How it works (intuition)

  • Think of Wall Erode Threshold as “how isolated can a wall be before it crumbles.”
  • Think of Wall Regrow Threshold as “how surrounded must a floor be before it fills back in.”
  • Using 8-way neighbors blends diagonals into decisions (rounded caverns).
    Using 4-way limits influence to N/S/E/W (blockier patterns).

Tips & pitfalls

  • Start with Initial Wall Chance ~0.55, Erode=4, Regrow=5, Iterations=5, 8 neighbors - then tweak.
  • If caves are too open: increase Initial Wall Chance or Regrow Threshold, or add Iterations.
  • If caves are too tight: decrease Initial Wall Chance or Regrow Threshold, or add Erode (raise it) and Iterations.
  • Prefer 8 neighbors for natural caverns; 4 neighbors for retro/grid vibes.
  • Chain with filters:
    • FilterCellsKeepLargestRegions to ensure one contiguous cave.
    • FilterCellsRemoveSmallRegions to clear specks.
    • FilterCellsJoinAllRegions to connect pockets with corridors.
    • FilterCellsBridgeDiagonals to fix corner-only contacts for 4-way pathing.
  • For reproducible results, set a seed first with Random → Random Init State.