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Cursed 16mm Spectral Ectoplasm & Blood-Moon Bloom (Halloween Agentic VFX)
Project Overview
Created for the Invideo Agentic Effects Challenge. Instead of spending hours keyframing complex horror VFX and displacement maps in traditional software, I directed Invideo Editor's AI Timeline Agent to build and compile a custom WebGL shader effect directly on the footage.
1. Primary Effect Built
"Cursed 16mm Spectral Ectoplasm & Blood-Moon Bloom"
A custom shader-based horror transformation that:
Isolates specular highlights above a 75% luminance threshold and stretches them into upward-drifting ghostly spirit vapor trails using 2D Simplex noise.
Remaps color curves to a supernatural horror palette: crushed inky blacks, deep blood-crimson midtones, and inverted bone-white/cyan specular highlights.
Adds an authentic 16mm photochemical edge halation bleed, organic archival grain, and an eerie low-frequency heartbeat pulse.
Exposes interactive inspector controls directly on the timeline for manual fine-tuning (Zero manual rotoscoping required).
2. Process Note: Starting Footage
Source Footage: High-contrast 9:16 vertical footage of a hooded silhouette in a dark atmospheric setting, featuring a sharp rim-light outline and deep black shadows.
Creative Direction: The high chiaroscuro contrast allows the shader to isolate the bright silhouette edges without needing messy object tracking.
3. What I Asked the Agent to Do
I prompted the Invideo Timeline Agent to write and compile the custom shader logic directly onto the clip on my editable timeline:
"Build and compile a custom 'Cursed 16mm Spectral Ectoplasm & Blood-Moon Bloom' WebGL shader directly on my selected clip on the timeline:
Spectral Ectoplasm Vapor: Sample highlights >75% luminance and stretch into upward-drifting spirit vapor trails using 2D simplex noise turbulence.
Blood-Moon Tone Remap: Crush shadows to deep black, shift midtones to dark crimson, and invert peak highlights to an ethereal bone-white / cyan glow.
Paranormal Pulse: Add a subtle low-frequency exposure heartbeat throb with micro-frame flicker.
Cursed 16mm Finish: Add intense photochemical red halation along high-contrast silhouette edges and organic archival grain.
Expose Inspector Controls: Trail Height, Vapor Speed, Blood Tint Intensity, Invert Threshold, and Grain Mix. Do not generate images; compile this as an interactive shader on my editable timeline."
4. What I Refined Myself (Human Direction)
Once the agent compiled the shader and created custom timeline controls, I manually adjusted the parameters in the inspector:
Highlight Threshold: Fine-tuned to 80% to ensure only the rim light on the hood caught fire.
Ectoplasm Trail Height: Pulled to 65% to let the ghostly vapor stretch cleanly into the negative space above the subject.
Blood-Moon Tint Intensity: Dialed to 75% to achieve a deep, cinematic A24-style crimson grade.
Timing & Audio: Trimmed cuts to the audio beat and added custom sound design risers.
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