fractals-edm-showcase

name	fractals-edm-showcase
description	Create a high‑energy fractal showcase video with a synthetic EDM soundtrack, including custom Seahorse and Elephant‑jet visuals, a slow zoom, and final audio‑video merge.
version	1
author	Hermes Agent

Purpose

When to Use

Create a high‑energy fractal showcase video with a synthetic EDM soundtrack, including custom Seahorse and Elephant‑jet visuals, a slow zoom, and final audio‑video merge.

Overview

This skill contains a reusable operational workflow. Follow the existing task-specific steps and examples in the sections below.

Pitfalls

• Do not hardcode credentials, tokens, or personal secrets.
• Verify external service URLs, paths, and permissions before making changes.
• Keep generated outputs reproducible and record input assumptions.

Verification

• Confirm required inputs and credentials are available.
• Run the smallest safe command or example before scaling up.
• Check produced files, API responses, or plots before reporting success.

This skill automates the end‑to‑end pipeline for a 55‑second Manim animation that displays several fractals (Mandelbrot, Sierpinski, Barnsley fern, Seahorse Valley, Elephant Valley) and synchronises it with a fast, rock‑inspired EDM track generated entirely in Python.

Prerequisites

• Python 3.11 with a virtual environment containing manim, numpy, matplotlib, scipy, Pillow, and ffmpeg in the system PATH.
• The project directory ~/fractals-animation/ (created beforehand).
• Sufficient RAM/VRAM for the chosen Manim render quality (480p15 for drafts, 1080p60 for HQ).

Step‑by‑step Procedure

1️⃣ Generate the synthetic EDM track

1. Create ~/fractals-animation/audio/generate_edm_track.py with the following logic (excerpt):
   • Set BPM = 140 (fast, rocking).
   • Build four tracks: kick, snare, hi‑hat (16th‑note pattern), synth lead.
   • Apply an exponential decay envelope to the kick, white‑noise burst for snare, short square‑wave bursts for hi‑hat.
   • Add a side‑chain‑style ducking envelope on the synth lead triggered by each kick.
   • Add a low‑frequency LFO wobble to the synth bass for “rock” feel.
   • Mix to a stereo NumPy array, write to edm_fast.wav (44.1 kHz, 16‑bit).
2. Convert to AAC for MP4 muxing:

   ffmpeg -y -i edm_fast.wav -c:a aac -b:a 192k edm_fast.aac
   

3. Trim to exactly 55 seconds (matches video length) to avoid padding clicks:

   ffmpeg -y -i edm_fast.aac -ss 0 -t 55 -c copy edm_fast_trimmed.aac
   

2️⃣ Add custom fractal image helpers

Edit ~/fractals-animation/script.py:

• Insert save_seahorse: uses a polar parametric equation to produce a magenta point‑cloud PNG.
• Insert save_elephant_jet: loads the existing barnsley_elephant.png, converts to greyscale, resizes to 512×512, applies Matplotlib’s jet colormap, and saves elephant_jet.png.
• Ensure both helpers are called only if their output files do not already exist (caching).

3️⃣ Update the Manim scene

In the FractalsShowcase class, replace the original elephant block with:

elephant = ImageMobject(ELEPHANT_JET_IMG).scale(2.0)
self.play(FadeIn(elephant, scale=0.8), run_time=2.0)
# Slow zoom out over ~30 s while staying centred
self.play(elephant.animate.scale(0.5).move_to(ORIGIN),
          run_time=30.0, rate_func=linear)
self.wait(2.0)
self.play(FadeOut(elephant, scale=0.8), run_time=2.0)
self.wait(0.5)

• Insert a call to show(SEAHORSE_IMG, duration=5) before the elephant block if you want the Seahorse displayed.
• Keep the “clear‑before‑next” caption policy (no overlapping text).

4️⃣ Render the draft video

source ~/.venvs/manim/bin/activate
manim -ql ~/fractals-animation/script.py FractalsShowcase
# Output will appear at:
# ~/fractals-animation/media/videos/script/480p15/FractalsShowcase.mp4

If you need a faster preview, you can reduce the camera frame_width or lower the DPI inside the image‑saving helpers.

5️⃣ Merge audio & video

ffmpeg -y -i ~/fractals-animation/media/videos/script/480p15/FractalsShowcase.mp4 \
       -i ~/fractals-animation/audio/edm_fast_trimmed.aac \
       -c:v copy -c:a aac -b:a 192k -filter:a "volume=0.9" \
       ~/fractals-animation/media/videos/script/480p15/FractalsShowcase_with_EDM_fast.mp4

Verify that the resulting file plays for exactly ~55 s and that the beat lines up with the zoom.

6️⃣ Optional high‑quality render

After user approval of the draft:

manim -qh ~/fractals-animation/script.py FractalsShowcase
# HQ video will be stored under media/videos/script/1080p60/
ffmpeg -y -i ~/fractals-animation/media/videos/script/1080p60/FractalsShowcase.mp4 \
       -i ~/fractals-animation/audio/edm_fast_trimmed.aac \
       -c:v copy -c:a aac -b:a 192k \
       ~/fractals-animation/media/videos/script/1080p60/FractalsShowcase_with_EDM_fast_HQ.mp4

Pitfalls & Work‑arounds

• Memory blow‑up: Rendering at 1080p60 with many high‑resolution PNGs can exceed RAM. Reduce the number of points in save_seahorse (e.g., points=100000).
• Audio click at cut‑point: Always use the -c copy trim method; never re‑encode a trimmed segment, otherwise a tiny click may appear.
• Zoom speed mismatch: The run_time for the zoom should be roughly the remaining video duration after previous sections. Adjust run_time if you add/remove other clips.
• FFmpeg version: Ensure you have FFmpeg ≥ 4.4; older versions mishandle AAC‑in‑MP4 muxing.

Verification Checklist

• edm_fast_trimmed.aac is exactly 55 seconds (ffprobe shows duration=55.00).
• Draft video (FractalsShowcase.mp4) plays without stalls and shows Seahorse and Elephant‑jet centred.
• Final merged video file size ≤ 2 MB (draft) and ≤ 10 MB (HQ).
• Audio is audible and sync‑locked with the elephant zoom (beat hits on zoom milestones).

References

• Manim documentation: https://docs.manim.community/
• FFmpeg audio‑video merge guide: https://trac.ffmpeg.org/wiki/Concat
• Simple EDM synthesis example (public domain): https://github.com/karpathy/nnf-synth

---

End of skill