Random Scene Duration Ladder Generator

Description

Assign supplied distinct scene briefs a strictly increasing or decreasing duration ladder with exact cumulative timing and a preflighted session limit.

A structured creative brief combines a supplied bank of fictional material with explicit sequencing, timing, or compatibility rules. IDs and tags make those constraints inspectable; they do not assess the artistic meaning or quality of a scene.

Assign supplied distinct scene briefs a strictly increasing or decreasing duration ladder with exact cumulative timing and a preflighted session limit.

When to use this tool

Use this generator to create reproducible scene duration ladder 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 scenes, count, baseSeconds, incrementSeconds, direction, sessionLimitSeconds 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 scenes, rounds, totalSeconds. Use the conventions below and keep answer-bearing fields separate when presenting an exercise.

Construct an arithmetic ladder of scene durations from baseSeconds and incrementSeconds, reversing it for decreasing mode. Sample scenes without replacement, assign consecutive intervals, and return pairs of scenes as rounds.^[1]

Input field	Meaning and units	Accepted input
scenes	Scenes	Required. Array of Object; no unknown keys.; minimum items 1; maximum items 32.
scenes[].id	Literal identifier used to match records, independently of their display labels.	Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 64.
scenes[].brief	Brief	Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 1024.
count	Requested count; the mechanics explain whether one draw expands into several returned records.	Required. Safe integer; minimum 1; maximum 32.
baseSeconds	Base Seconds	Required. Safe integer; minimum 1; maximum 9007199254740991.
incrementSeconds	Increment Seconds	Required. Safe integer; minimum 1; maximum 9007199254740991.
direction	Direction	Required. Text; one of "increasing", "decreasing".
sessionLimitSeconds	Session Limit Seconds	Required. Safe integer; minimum 1; maximum 9007199254740991.
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
scenes	Scenes	Required. Array of Object; no unknown keys.; minimum items 1; maximum items 32.
scenes[].id	Literal identifier used to match records, independently of their display labels.	Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 64.
scenes[].brief	Brief	Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 1024.
scenes[].seconds	Seconds	Required. Safe integer; minimum 1; maximum 9007199254740991.
scenes[].startSecond	Start Second	Required. Safe integer; minimum 0; maximum 9007199254740991.
scenes[].endSecond	End Second	Required. Safe integer; minimum 1; maximum 9007199254740991.
scenes[].timingLabel	Timing Label	Required. Text.
rounds	Rounds	Required. Array of Array of Text; minimum UTF-16 length 1; maximum UTF-16 length 64.; minimum items 1; maximum items 2.; minimum items 1; maximum items 16.
totalSeconds	Total Seconds	Required. Safe integer; minimum 1; maximum 9007199254740991.
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": {
    "scenes": [
      {
        "id": "arrive",
        "brief": "A ship arrives"
      },
      {
        "id": "leave",
        "brief": "A ship leaves"
      }
    ],
    "count": 2,
    "baseSeconds": 15,
    "incrementSeconds": 10,
    "direction": "decreasing",
    "sessionLimitSeconds": 40,
    "seed": 42
  },
  "output": {
    "scenes": [
      {
        "id": "leave",
        "brief": "A ship leaves",
        "seconds": 25,
        "startSecond": 0,
        "endSecond": 25,
        "timingLabel": "25 seconds"
      },
      {
        "id": "arrive",
        "brief": "A ship arrives",
        "seconds": 15,
        "startSecond": 25,
        "endSecond": 40,
        "timingLabel": "15 seconds"
      }
    ],
    "rounds": [
      [
        "leave",
        "arrive"
      ]
    ],
    "totalSeconds": 40,
    "randomness": {
      "seed": 42,
      "source": "seed"
    }
  }
}

Limitations and assumptions

The exact integer duration sum must fit sessionLimitSeconds and safe integer range. Requested scene count cannot exceed the supplied bank; timing does not evaluate artistic suitability.
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 Scene Duration Ladder Generator — tool.io

Similar or alternative tools

Random Prop-Only Scene Challenge Generator
Draw distinct supplied prop descriptions and a dramatic objective into timed focus briefs; callers review physical suitability and permitted handling.
Random Silent Scene Constraint Cards Generator
Combine supplied objectives, locations, and nonverbal constraints into timed scene cards with explicit forbidden spoken-word rules and chunked rounds.