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Bend a star field around a dark horizon and a glowing tilted disk in an editable cosmic motion study. A radial lens mapping resamples the star field around an occluding central horizon. An emissive tilted disk, bright ring and art-directed upper arc are evaluated separately, while the framing changes over time. The optics are a visual approximation rather than relativistic ray tracing. Reuse supplied assets or quote new media through PopNow.

Uses PopNow for
Images · Music & voice
Needs
Python 3 · FFmpeg

Generation is optional when you have suitable input material.

v1.0.0 · Updated Oct 25, 2026 · 2.0 MB · Use it for personal and client work; please don't resell or share the package.

What you get

  1. An editable 8-second 720p sample and local MP4 renderer, silent.

  2. Background sampling, lens distortion, disk structure and the motion envelope are already coordinated. Lens strength changes the actual image mapping, so you can explore the effect with an owned star photograph instead of replacing a finished clip.

  3. A six-frame contact sheet, render receipt and input self-check.

Good for

  • Cosmic postcards and short science-inspired art films
  • Testing an owned sky image inside a controllable lens effect

Not for

  • This is an artistic radial warp with an authored disk, not a geodesic or general-relativity simulation. It does not infer real three-dimensional space from a background photograph.

How it works

Includes a local renderer

  1. Choose the material

    Use the procedural star field or provide a local background image. The disk and horizon are generated locally.

  2. Shape the motion

    Edit the documented project controls, then validate the exact settings. Lens strength from 0.6 to 1.6 changes horizon size and radial warping.

  3. Render and review

    Export locally to MP4, inspect the contact sheet and watch the whole film. Inspect the warped background, bright ring and disk throughout the film, checking for distracting clipping or abrupt seams.

How the workflow runs

How Black Hole Postcard works

A radial lens mapping resamples the star field around an occluding central horizon. An emissive tilted disk, bright ring and art-directed upper arc are evaluated separately, while the framing changes over time. The optics are a visual approximation rather than relativistic ray tracing.

What's inside the skill

What you can change

  • Lens strength from 0.6 to 1.6 changes horizon size and radial warping.
  • Disk tilt from 0.12 to 0.55 controls its projected shape.
  • Disk speed from 0.1 to 1.2 changes its rotating pattern.
  • The seed changes procedural stars; background supplies an owned image instead.

What to review before delivery

  • The local self-check compares three frame samples after a meaningful input change and rejects its documented invalid case.
  • Output protection rejects overlap with input files and preserves existing sidecars unless overwrite is explicit.
  • Inspect the warped background, bright ring and disk throughout the film, checking for distracting clipping or abrupt seams. This final visual review is manual.

See the package files

These are selected working files from this edition, with their actual role. The complete download also contains instructions and applicable license notices.

  • The task-specific motion mechanism and supported inputs.

    scripts/scene.py

  • Protected MP4 export, contact sheet and hash receipt.

    scripts/runtime.py

  • Editable settings used by the supplied sample.

    examples/project.json

  • Actual changed-frame, invalid-input and output-protection checks.

    scripts/selftest.py

  • Input ranges, material placement and honest limits.

    references/inputs.md

Why use this skill

Start with this package

Background sampling, lens distortion, disk structure and the motion envelope are already coordinated. Lens strength changes the actual image mapping, so you can explore the effect with an owned star photograph instead of replacing a finished clip.

What PopNow adds

Use PopNow for the missing Images, Music & voice in this workflow. Keep adequate material you already own, then bring new assets back into the editing and assembly steps described here.

Compare the options

A prompt, your own skill, or this workflow?

Start with a prompt

Your agent can create from a plain request. The brief, visual rules, asset choices, output format and review process still need to be established for that project.

Write your own skill

You choose and maintain the reusable instructions, defaults, file structure and checks. This is useful when your process needs different rules or integrations.

A workflow created for PopNow

This workflow was built for PopNow. Its source files, included dependencies and applicable notices are part of the package; the scope described below belongs to this edition.

Guide reviewed Oct 25, 2026

What will this cost?

The procedural star example renders locally. A new star-field image or optional soundtrack can be quoted through PopNow if needed; an adequate owned background is reused without another image generation request.

Generation is optional when you have suitable input material. Free skill. New media is quoted before it runs.

The skill package

Free to install under your account's download allowance. The package license covers your own and client work; redistribution is excluded.

Existing assets and local work

Reusing suitable assets, editing files and running local assembly do not call a PopNow generation model. Your computer and any required runtime still do the work.

New AI images, clips or sound

Quoted for the actual model, inputs, count, duration and resolution. Extra alternatives, revisions or optional enhancement passes can add generation requests.

Your agent and hosting

Any subscription, hosted computer, deployment or other provider fee belongs to that service. Installing this skill does not include those services.

Check the cost of your version first

Your assistant can inspect the available models and quote the exact request first. You choose which optional passes to include and approve spending before generation.

Ask your assistant

  • Use the PopNow skill "Black Hole Postcard" for my project. List the inputs you can reuse, quote only the missing media, show the quoted total and flag any unpriced steps. Separate optional enhancements, and wait for my approval before starting anything paid.

How PopNow billing works

Connections using a PopNow API key, including API-key MCP connections, spend from the separate API balance in USD. A ChatGPT or Claude connection authorized through OAuth spends website credits. These balances are separate; the quote shown by your connection is the approval basis.

Download allowances and current account conditions apply. A free package does not mean unlimited free generation.

See model ratesAPI USD balanceWebsite credit packs

How to use it

You say

  • Use the PopNow skill "Black Hole Postcard" (black-hole-postcard) for this: Render the supplied 8-second example. Make a second version with disk_tilt set to 0.5. Show the changed motion and quote any missing media before generation.

Then try

  • Show how the changed setting affects the actual motion.

  • Keep my adequate source material and prepare an optional soundtrack quote.

What to have ready

  • Use the procedural star field or provide a local background image. The disk and horizon are generated locally.
  • Python 3, Pillow, NumPy, FFmpeg and ffprobe
  • The project controls listed in the input contract

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Questions

Is the black hole scientifically accurate?

No. The package uses a radial image warp and an authored emissive disk. It does not solve relativistic light paths.

Can I use a real sky photograph?

Yes, as background. The renderer fits it to the frame and samples it through the lens mapping; the input remains a two-dimensional image.

Are the stars generated by an image model?

The default stars are procedural. You only need a generation quote if you choose to create a new background or soundtrack.

What is already packaged in Black Hole Postcard?

The task-specific motion mechanism and supported inputs. Protected MP4 export, contact sheet and hash receipt. Editable settings used by the supplied sample. Actual changed-frame, invalid-input and output-protection checks. Input ranges, material placement and honest limits.

Which parts of Black Hole Postcard can add a charge?

The procedural star example renders locally. A new star-field image or optional soundtrack can be quoted through PopNow if needed; an adequate owned background is reused without another image generation request. Connections using a PopNow API key, including API-key MCP connections, spend from the separate API balance in USD. A ChatGPT or Claude connection authorized through OAuth spends website credits. These balances are separate; the quote shown by your connection is the approval basis.

How does Black Hole Postcard differ from writing a prompt or my own skill?

Background sampling, lens distortion, disk structure and the motion envelope are already coordinated. Lens strength changes the actual image mapping, so you can explore the effect with an owned star photograph instead of replacing a finished clip.