layer-video-looks

Layer Video Looks

Overview

A look is the finish that makes separate shots read as one piece. On Layer it lives in the timeline: every video and image item in render_video_timeline takes an effects list plus its own blur, brightness, saturation, hue and opacity fields. No model runs to apply them, so a look is exact to repeat; the render is still priced by estimate_video_timeline_price.

Assembly itself (sequence, transitions, overlays, audio) is layer-video-timeline. This skill covers the finish on top of it. A look the timeline cannot make, such as relighting a shot or restyling its content, is a generation: see layer-video-fixes.

If a sibling skill named here is missing from your available skills, ask the user to install it (npx skills add layerai/skills --skill <name>); unattended, proceed from tool schemas and flag the gap.

Quick reference

Look	Effects, in this order
Brand wash	duotone with darkColor and lightColor in brand colours, or tint with amount
Retro CRT	scanlines, then noise, then a light chromaticAberration
Film	noise (grain), vignette, lightLeak
Glitch hit on a cut	tvSignalOff or a strong chromaticAberration on a short item at the cut
Green or blue screen	colorKey first, with keyColor set to the screen
Cut-out logo or character	dropShadow or outline on an image that has transparency
Dreamy highlights	glow with a threshold so only the bright parts bloom
Plain grade	Item fields: brightness, saturation, hue; contrast, exposure, vibrance effects

Every effect is {type: "<name>", ...params} with camelCase params, and every param has a default, so {type: "vignette"} alone is valid. Colours are {red, green, blue, alpha} objects, 0 to 255. blur, brightness, saturation, hue and opacity are item fields, not effects: brightness and saturation are multipliers from 0 to 2 (1 unchanged), hue rotates -180 to 180 degrees.

render_video_timeline takes {workspace_id, template, videos, images, audios}. template is {width, height, fps, tracks: [{id, name, items, transitions}]}; an item is {id, type, start_frame, duration_in_frames} plus file_id or slot, and optionally layout {left, top, width, height}, effects, start_from_in_seconds to trim a clip's head, and volume; a solid takes color {red, green, blue, alpha}. The render returns a generation_id for get_generation_run.

Order is the look

Effects apply in list order, each on the result of the one before. Order changes the picture:

• Key first. colorKey must see the screen's true colour. A tint or exposure ahead of it shifts the green and the key leaves patches behind.
• Grade before texture. Put tint, duotone and contrast ahead of noise and scanlines, so the grain sits on top of the colour instead of being recoloured by it.
• Distortion last. wave, fisheye and zoomBlur bend whatever reaches them; place them after the texture so the scanlines bend with the picture.

One list, every clip

A look holds only if every clip that shares it carries the same effects list with the same params. Build the list once and copy it onto each item. A second clip with a slightly different tint amount reads as a mismatch, which is worse than no look at all.

Grade toward the shots, not away from them. Shots generated at different times differ in exposure and saturation; level them first with the item's brightness and saturation fields, then apply the shared list.

Params are fixed for the whole item

The timeline has no keyframes. An effect's params hold for the item's whole span: a shine with progress: 0.5 is a sheen parked in the middle, not one that sweeps across, and lightLeak progress is one phase of the leak, held.

Two ways to get movement:

• Stepped items. Split the span into several short items of the same file on one track, each with start_from_in_seconds continuing where the last stopped, and raise progress on each. Four to six steps read as motion on a short sheen.
• Generate it. A sweep that must be smooth is a video generation with the motion in the prompt (layer-video), not a timeline effect.

The same split confines an effect to a moment: cut the clip into before, hit and after items on one track, and give only the few-frame hit item tvSignalOff. Do not stack the pieces on separate tracks; items on one track must not overlap in time.

Keying a screen

colorKey defaults to green ({red: 0, green: 255, blue: 0}); set keyColor to {red: 0, green: 0, blue: 255} for a blue screen. Tune in the order the schema gives: raise similarity when patches of the screen remain, lower it when the subject's edges get eaten, and raise spillSuppression when a coloured fringe stays on the subject. smoothness softens the keyed edge.

Tracks composite in reverse order, so Track 1 is on top. The keyed clip goes on a track above the background it should reveal.

Filling around a contained clip

A 16:9 clip in a 9:16 frame leaves bars. The schema's own fix: put a second copy of the clip on a lower track with a full-frame layout, is_auto_layout: false, content_fit: "cover", a high blur, volume: 0, and its brightness lowered, then show the clip above it with content_fit: "contain". The frame fills with the clip's own colours instead of black.

Worked example

"Give these four approved gameplay shots a retro arcade look, and put our presenter, shot on green screen, over the last one."

1. All five clips came from earlier runs, so each has a file_id; nothing is uploaded.
2. Build one list for the gameplay clips: [{type: "contrast", amount: 1.15}, {type: "scanlines", amount: 0.2, spacing: 4}, {type: "noise", amount: 0.12}, {type: "chromaticAberration", amount: 3}]. Copy it unchanged onto all four gameplay items on Track 2.
3. The presenter goes on Track 1, spanning the last shot, with [{type: "colorKey"}, {type: "scanlines", amount: 0.2, spacing: 4}, {type: "noise", amount: 0.12}]: key first, then the same texture so the presenter sits in the same world.
4. A three-frame tvSignalOff item at the cut into the last shot, split from the clip as above.
5. estimate_video_timeline_price with the full input. Present the table; above 20 CUs wait for an explicit yes.
6. render_video_timeline with the same input. Poll get_generation_run with the returned generation_id at the interval it gives, never a fixed sleep.
7. Watch it end to end. If green patches remain on the presenter, raise similarity a step and re-render; if the hair edge is eaten, lower it.

Common mistakes

• A different effect list, or different params, on clips meant to share a look.
• A tint or exposure ahead of colorKey, so the screen no longer matches the key colour.
• Expecting shine or lightLeak to move across a clip; params are fixed per item.
• Putting the keyed clip on a lower track than its background.
• dropShadow or outline on a clip with no transparency; the schema says they work best on cut-outs.
• Glitching a whole clip when the hit belongs on a few frames at the cut.
• Reaching for a generation to recolour footage the timeline can already grade.
• Uploading clips that Layer generated and that already carry a file_id.