Adobe After Effects

Adobe After Effects Motion Graphics AI Skill Guide (Claude)

Overview & Engine Architecture

Adobe After Effects is a layer-based compositing and motion design tool organized around Projects → Compositions → Layers, with expressions (JavaScript-like), effects, masks/shapes, 3D cameras, and the Render Queue / Media Encoder delivery path. Automation uses ExtendScript (JSX) against the AE DOM (app.project, CompItem, AVLayer). Claude operates as a Principal Motion Systems Engineer, specializing in comp scaffolding, expression-driven rigs, batch render queue setup, and Essential Graphics template hygiene.

After Effects Composition & Scripting Stack

┌─────────────────────────────────────────────────────────────┐
│                 After Effects Architecture                  │
│                                                             │
│  Project Graph                                              │
│  ├── FootageItem / FolderItem / CompItem                    │
│  ├── Layer types (AV, Shape, Text, Camera, Light, Null)     │
│  └── Properties / Keyframes / Expressions                   │
│                                                             │
│  Automation                                                 │
│  ├── ExtendScript DOM + JSON polyfills as needed            │
│  ├── Expressions engine (time, value, thisComp, thisLayer)  │
│  └── renderQueue items & output modules                     │
│                                                             │
│  Delivery                                                   │
│  ├── Render Queue / AME                                     │
│  ├── Essential Graphics (.mogrt)                            │
│  └── Dynamic Link with Premiere                             │
└─────────────────────────────────────────────────────────────┘

Operational Capabilities & Agent Directives

1. Comp Spec First: Define width, height, frame rate, and duration before creating layers.
2. Expressions vs Keyframes: Prefer expressions for procedural/linked motion; keyframes for intentional animation curves.
3. Render Queue Automation: Create OutputModule settings explicitly (format, path, post-render actions).
4. Null / Parent Rigs: Build controller nulls for reusable motion systems instead of hardcoding layer indices.
5. Version Portability: Avoid undocumented scripting quirks; test JSX against the studio's AE major version.

Production ExtendScript: Build Lower-Third Comp + Queue Render

// ==============================================================================
// After Effects ExtendScript: create a lower-third comp and add to render queue
// ==============================================================================
(function () {
  app.beginUndoGroup("Create Lower Third");

  var proj = app.project;
  var comp = proj.items.addComp("LT_Hero", 1920, 1080, 1.0, 5.0, 30);
  var solid = comp.layers.addSolid([0.05, 0.55, 0.9], "Bar", 640, 96, 1.0);
  solid.position.setValue([420, 860]);

  var textLayer = comp.layers.addText("Product Launch");
  var textProp = textLayer.property("Source Text");
  var textDoc = textProp.value;
  textDoc.fontSize = 48;
  textDoc.fillColor = [1, 1, 1];
  textDoc.font = "Arial-BoldMT";
  textProp.setValue(textDoc);
  textLayer.position.setValue([420, 860]);

  // Simple slide-in via expression on Position
  solid.property("Position").expression =
    "var t = time; var x = ease(t, 0, 0.6, -200, 420); [x, 860]";

  var rq = app.project.renderQueue.items.add(comp);
  var om = rq.outputModule(1);
  // Apply a named template if present in the user's AE install:
  try {
    om.applyTemplate("H.264 - Match Render Settings - 15 Mbps");
  } catch (e) {
    // Fallback: leave default module; user picks preset
  }
  om.file = new File("~/Desktop/LT_Hero_Out.mp4");

  app.endUndoGroup();
  alert("Lower-third comp created and queued: " + comp.name);
})();

Technical Troubleshooting Matrix

Essential Expression Snippets

// Smooth follow of another layer's position
var target = thisComp.layer("Controller");
ease(time, 0, 1, target.transform.position, target.transform.position)
// Better: use linear interpolation toward target each frame via loopOut or valueAtTime patterns

Essential Paths

• Scripts: AE Scripts / ScriptUI Panels
• Preferences: Media & Disk Cache
• mogrt: Essential Graphics export for Premiere

Agent Operational Directive

MANDATORY: Wrap project mutations in beginUndoGroup / endUndoGroup. Set comp specs explicitly. Treat output module template names as environment-specific and fail gracefully when missing.