Random Paper Fan Panel Pattern Generator

Description

Build equal accordion panels from supplied motif boxes with matching caller edge tags and alternating fold labels; tag compatibility is not graphical continuity certification.

Procedural artwork expresses a visual idea through coordinates, repeated motifs, colors, or explicit placement constraints. A coordinate plan can be checked and reproduced before rendering, while physical material behavior and fabrication require separate information.

Build equal accordion panels from supplied motif boxes with matching caller edge tags and alternating fold labels; tag compatibility is not graphical continuity certification.

When to use this tool

Use this generator to create reproducible paper fan panel pattern cases from the supplied model or bank. Inspect the returned evidence before using cases in a test or exercise.

How to use the tool and how it works

Supply width, height, panelCount, motifs, leftEdge, rightEdge, firstFold in the field shapes below. Set seed when you need an explicit replay.
Run the tool and correct any input error. For generated controls, distinguish a successful fixture containing an invalid case from failure to generate the fixture.
Read panels, folds, sheetArea. Use the conventions below and keep answer-bearing fields separate when presenting an exercise.

Divide the sheet into equal-width panels and use bounded search to select fitting motifs whose left and right edge labels match neighboring panels and required outer edges. Center each motif and alternate mountain and valley fold labels from firstFold.^[1]

Input field	Meaning and units	Accepted input
width	Width	Required. Finite number; strictly above 0.
height	Height	Required. Finite number; strictly above 0.
panelCount	Panel Count	Required. Safe integer; minimum 2; maximum 32.
motifs	Motifs	Required. Array of Object; no unknown keys.; minimum items 1; maximum items 16.
motifs[].id	Literal identifier used to match records, independently of their display labels.	Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 80.
motifs[].width	Width	Required. Finite number; strictly above 0.
motifs[].height	Height	Required. Finite number; strictly above 0.
motifs[].leftEdge	Left Edge	Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 80.
motifs[].rightEdge	Right Edge	Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 80.
leftEdge	Left Edge	Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 80.
rightEdge	Right Edge	Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 80.
firstFold	First Fold	Required. Text; one of "mountain", "valley".
seed	Optional numeric seed; takes precedence over context randomness. Without either, use the fixed tool.io default seed.	Optional. Safe integer.

Output field	Interpretation	Returned shape
panels	Panels	Required. Array of Object; no unknown keys.; minimum items 2; maximum items 32.
panels[].index	Index	Required. Safe integer; minimum 0; maximum 31.
panels[].motifId	Motif Id	Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 80.
panels[].x	X	Required. Finite number.
panels[].y	Y	Required. Finite number.
panels[].width	Width	Required. Finite number; strictly above 0.
panels[].height	Height	Required. Finite number; strictly above 0.
panels[].motifX	Motif X	Required. Finite number.
panels[].motifY	Motif Y	Required. Finite number.
panels[].motifWidth	Motif Width	Required. Finite number; strictly above 0.
panels[].motifHeight	Motif Height	Required. Finite number; strictly above 0.
panels[].leftEdge	Left Edge	Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 80.
panels[].rightEdge	Right Edge	Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 80.
folds	Folds	Required. Array of Object; no unknown keys.; minimum items 1; maximum items 31.
folds[].x	X	Required. Finite number.
folds[].kind	Kind	Required. Text; one of "mountain", "valley".
sheetArea	Sheet Area	Required. Finite number; strictly above 0.
randomness	Replay metadata: source is seed or context; seed is the normalized 32-bit seed or null for a context source.	Required. Object; no unknown keys.
randomness.seed	Optional numeric replay seed; normalization and precedence are explained below.	Required. Safe integer. or Null.
randomness.source	Source	Required. Text; one of "context", "seed".

An explicit safe-integer seed takes precedence over injected context randomness and is normalized to an unsigned 32-bit integer. With no seed and no context source, replay uses the fixed tool.io default seed. A context source must return finite values from zero inclusive to one exclusive; its advancing state must be retained separately. randomness records the source and normalized seed, or null for context. These generators are not cryptographic random sources.

json

{
  "input": {
    "width": 4,
    "height": 3,
    "panelCount": 2,
    "motifs": [
      {
        "id": "A",
        "width": 2,
        "height": 3,
        "leftEdge": "x",
        "rightEdge": "x"
      },
      {
        "id": "B",
        "width": 2,
        "height": 3,
        "leftEdge": "x",
        "rightEdge": "x"
      }
    ],
    "leftEdge": "x",
    "rightEdge": "x",
    "firstFold": "mountain",
    "seed": 42
  },
  "output": {
    "panels": [
      {
        "index": 0,
        "motifId": "B",
        "x": 0,
        "y": 0,
        "width": 2,
        "height": 3,
        "motifX": 0,
        "motifY": 0,
        "motifWidth": 2,
        "motifHeight": 3,
        "leftEdge": "x",
        "rightEdge": "x"
      },
      {
        "index": 1,
        "motifId": "A",
        "x": 2,
        "y": 0,
        "width": 2,
        "height": 3,
        "motifX": 2,
        "motifY": 0,
        "motifWidth": 2,
        "motifHeight": 3,
        "leftEdge": "x",
        "rightEdge": "x"
      }
    ],
    "folds": [
      {
        "x": 2,
        "kind": "mountain"
      }
    ],
    "sheetArea": 12,
    "randomness": {
      "seed": 42,
      "source": "seed"
    }
  }
}

Limitations and assumptions

Matching edge labels are caller metadata rather than geometric verification. Panel layout does not account for paper thickness, fold allowances, or physical fabrication safety.
A replay requires the same complete input and implementation. Randomized construction does not guarantee uniform coverage of every feasible output; finite samples can repeat unless a distinct-selection rule is explicitly stated.
The field tables state structural bounds; cross-field constraints and bounded search or output budgets also apply. Unknown keys are rejected where the object contract disallows them. Input errors are distinct from null fields and deliberate invalid controls in a successful output.

Alternative or Complementary methods

For a supplied example, inspect the returned construction or delegated check directly. To evaluate a consumer, also test cases chosen for its own boundaries; a generated finite corpus does not establish exhaustive coverage.

References

Tool behavior and example: Random Paper Fan Panel Pattern Generator — tool.io

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