Build Generation — Detail

Reference for Step 5 (builds) and the build-insertion portion of Step 6 (apply to deck). The illustration-rules Build Process section is auto-loaded — this file covers the script contract and deck insertion.

When to Use Builds

• Complex diagrams revealed one element at a time.
• Checklists that accumulate items across the talk.
• Step-by-step processes shown progressively.
• Any visual that benefits from gradual reveal (NOT PowerPoint animations — these are separate slides with separate images).

Backwards-Chaining Workflow

1. Start from the full slide image (illustrations/slide-NN.ext).
2. Use image editing to remove the last element → that's build step N-1.
3. Use the N-1 output as input, remove the next element → that's N-2.
4. Continue until build-00 (empty frame with title/borders only).
5. The final build step is a copy of the full slide image.

This backwards approach produces better results than building up from empty, because the model preserves the existing composition and style at each step.

Run

python3 skills/illustrations/scripts/generate-illustrations.py presentation-outline.md --build 5     # one slide
python3 skills/illustrations/scripts/generate-illustrations.py presentation-outline.md --build all   # all builds

Output: illustrations/builds/slide-NN-build-MM.jpg.

Edit-Prompt Authoring

Each build-NN: description is the erase instruction that turns the next stage into this one (backwards chaining), not a description of the end state. "Panel 2 revealed — sergeant, STILL? stamp" does not tell the model to erase anything, so the element survives and the stage comes out identical to the previous one.

• Name what to ERASE, then list what to KEEP — one Keep clause per element that must persist (page chrome, frames, already-revealed panels, borders, labels). This is component #3 of the Edit Prompt Safety rule, and it is mandatory: --build validates that every erase step carries a Keep clause and skips the slide with an error if one is missing.
• Pull the persisting elements from the slide's full Image prompt — the chrome that never appears in any build line (header bars, FIG labels, rules) is exactly what drifts when it isn't named.
• Include the visual-consistency clauses where relevant: "no parchment patch", "no new frames", "solid lines not dashed".
• The edit safety suffixes (DO NOT add any new elements, let background continue naturally) are auto-appended by the script — don't repeat them.
• Keep each build-NN: entry on a single line. The parser reads only the text up to the first newline, so any erase/Keep clauses on continuation lines are silently dropped — losing those preservation items, and failing Keep-clause validation outright when no Keep clause remains on the first line.

Example (slide with three trial panels revealed progressively — each entry is one line):

- build-02: Erase Panel 3 and the "LIFT +81 PTS" stamp. Keep the page chrome (header bar, FIG label, bottom rule). Keep the three panel frames and their TRIAL labels. Keep Panel 1 and Panel 2 content.
- build-01: Erase Panel 2 and the "STILL?" stamp. Keep the page chrome. Keep the three panel frames and labels. Keep Panel 1 content.
- build-00: Erase Panel 1 content and the "PLUGIN USELESS?" stamp. Keep the page chrome. Keep the three empty panel frames and their TRIAL labels.

For near-perfect results, use --fix for targeted corrections rather than regenerating the entire chain.

Deck Insertion

Build slides are inserted as separate slides in the deck (not PowerPoint animations). Each step is a full-bleed image:

Insertion rules:

• Insert in order: build-00, build-01, ..., build-N.
• All build slides use the BLANK layout, full-bleed image positioning at 16:9 slide dimensions (left=0, top=0, width=13.333", height=7.5").
• Speaker notes go ONLY on the final build step. Earlier steps get empty notes — the speaker advances through them silently or with ad-lib narration.
• Build slides count toward the slide budget — factor them in during presentation-creator's Phase 4 guardrails.
• The final build step (build-N) is visually identical to the parent slide. In the deck, the parent slide is replaced by its build sequence — not duplicated after it.