After Effects
After Effects is GUI software, so this skill delivers knowledge and ready-to-paste assets — expressions, rig setups, export checklists, diagnostic flows, naming schemes, and ExtendScript — rather than a rendered file. It is a hub covering four domains; route to the matching reference for depth and complete recipes.
Routing
| If the user wants to… | Go to |
|---|
| Write/debug an expression, rig sliders & nulls, build a MOGRT, export to Lottie | references/expressions.md (deep cookbook in references/expression-library.md) |
| Choose a codec/container, export with alpha, fix a black background, set bitrate, recover H.264 | references/export-recipes.md |
| Fix slow/laggy previews, slow renders, crashes, freezes, out-of-memory | references/performance-triage.md |
| Organize the project, relink missing footage, set naming/folders, batch-automate with .jsx | references/project-hygiene.md |
The .jsx automation scripts live in scripts/.
Expressions & rigging
Expressions are JavaScript evaluated on the property they are pasted on; value is that property's value, time is comp time in seconds, and index, thisLayer, thisComp are in scope. An expression overrides keyframes unless it incorporates value.
wiggle(2, 30); // 2 wiggles/sec, amplitude 30 (property units)
loopOut("cycle"); // repeat keyframed range forever; "pingpong" / "offset" / "continue"
seedRandom(index, true); // stable-but-unique per layer (timeless) before random()/wiggle()
thisComp.layer("Lead").transform.position.valueAtTime(time - 0.2 * index); // staggered echo
Inertial bounce (overshoot/settle after the last keyframe) and the full loop/wiggle/rigging set are in references/expressions.md.
Rig controllable motion: add a null with Slider / Checkbox / Color / Angle / Point control effects, then reference them and parent transforms to drive many layers from one.
ctrl = thisComp.layer("Controls");
amt = ctrl.effect("Intensity")("Slider"); // Checkbox → 1/0, Color → [r,g,b,a]
value * amt;
Expose those controls via Window → Essential Graphics and Export Motion Graphics Template (.mogrt) for Premiere/AE editors.
Export recipes
Two engines, and choosing wrong is the root of most export confusion:
- Render Queue (RQ) — masters/intermediates: ProRes, image sequences, lossless, alpha.
- Adobe Media Encoder (AME) — delivery: H.264 MP4, H.265, social presets.
Since AE CC 2014/2015 the native H.264 output module was removed from the RQ — make MP4s in AME, not the RQ. H.264/MP4 cannot store alpha, so a transparent comp exported to H.264 always fills with black; that is the classic "black background" complaint and not a bug. For transparency use ProRes 4444, a PNG/TIFF sequence, or HEVC-alpha (Safari) + VP9/WebM-alpha (Chrome), with Output Module Channels: RGB + Alpha.
Quick targets: editor handoff → ProRes 422 HQ; master/grade or alpha → ProRes 4444; web/social/client → H.264 via AME, VBR 2-pass (~10–16 Mbps 1080p, ~35–45 Mbps 4K). Full matrix, social specs, and step-by-step alpha exports in references/export-recipes.md.
Performance triage
Work top-down by symptom, cheapest fix first, and stop when it clears. Most settings are in Edit > Preferences (Win) / After Effects > Settings (Mac).
- Slow previews: Half/Third resolution → enable Multi-Frame Rendering → raise RAM allocation (leave ~6 GB for OS) → Adaptive fast previews → purge cache → Disk Cache on SSD/NVMe → solo heavy layers/effects → HW-accelerated decode → proxy heavy comps.
- Slow renders: confirm MFR on → RQ for masters / AME for delivery → HW decode H.264 → pre-render slow precomps → cheaper effects → transcode long-GOP to ProRes.
- Crashes/freezes: purge + empty disk cache → update NVIDIA Studio (not Game-Ready) drivers → reset prefs (
Ctrl/Cmd+Alt+Shift on launch) → pull third-party plugins → free disk space → disable MFR if MFR-specific → roll back AE after a bad update.
MFR needs several GB RAM per active core. Ordered flows, exact preference paths, and the proxy workflow are in references/performance-triage.md.
Project hygiene
Keep projects organized, portable, and automatable.
- Folders: numeric-prefixed bins (
01_Comps, 02_Precomps, 03_Footage, …, 99_Old) for stable sort order.
- Naming:
PROJECT_section_descriptor_v01; precomps PRE_; rename solids/nulls to their role (CTRL_master); no spaces/special chars for farm/cross-OS safety.
- Broken links: AE references footage by path, so moving files breaks links. Double-click a missing item → Replace Footage > File and AE relinks the whole folder at once; enumerate with
File > Dependencies > Find Missing Footage. Always hand off projects via File > Dependencies > Collect Files, never a bare .aep.
- ExtendScript (.jsx): wrap batches in
app.beginUndoGroup(...) / app.endUndoGroup(); apply effects by matchName (e.g. "ADBE Gaussian Blur 2"), not the display name. Ready scripts: scripts/batch-rename.jsx, scripts/sequential-offset.jsx, scripts/apply-effect-to-layers.jsx.
Full naming scheme, label-color system, relink/Collect-Files/Reduce workflows, and scripting setup in references/project-hygiene.md.
Reference files
references/expressions.md — expressions, rigging, MOGRT, Lottie/Media Encoder basics.references/expression-library.md — deeper expression cookbook: tuned inertial bounce, all loop variants, advanced wiggle, valueAtTime echoes, seedRandom grids, full rigging + coordinate spaces, MOGRT and Lottie/Bodymovin steps, Media Encoder presets.references/export-recipes.md — full codec/alpha/bitrate matrix, per-platform social specs, step-by-step transparency exports, AME preset cautions.references/performance-triage.md — ordered preview/render/crash flows, preference paths and values, MFR/GPU/disk-cache tuning, pre-render & proxy workflow.references/project-hygiene.md — folder template, naming and label systems, relink/Collect Files/Reduce details, scripting setup.scripts/batch-rename.jsx, scripts/sequential-offset.jsx, scripts/apply-effect-to-layers.jsx — ExtendScript automations.
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