--- name: threejs-postprocessing description: "Three.js Post-Processing workflow skill. Use this skill when the user needs Three.js post-processing - EffectComposer, bloom, DOF, screen effects. Use when adding visual effects, color grading, blur, glow, or creating custom screen-space shaders and the operator should preserve the upstream workflow, copied support files, and provenance before merging or handing off." version: "0.0.1" category: design tags: ["threejs-postprocessing", "three", "post-processing", "effectcomposer", "bloom", "dof", "screen", "effects"] complexity: advanced risk: caution tools: ["codex-cli", "claude-code", "cursor", "gemini-cli", "opencode"] source: community author: "sickn33" date_added: "2026-04-15" date_updated: "2026-04-25" --- # Three.js Post-Processing ## Overview This public intake copy packages `plugins/antigravity-awesome-skills-claude/skills/threejs-postprocessing` from `https://github.com/sickn33/antigravity-awesome-skills` into the native Omni Skills editorial shape without hiding its origin. Use it when the operator needs the upstream workflow, support files, and repository context to stay intact while the public validator and private enhancer continue their normal downstream flow. This intake keeps the copied upstream files intact and uses the `external_source` block in `metadata.json` plus `ORIGIN.md` as the provenance anchor for review. # Three.js Post-Processing Imported source sections that did not map cleanly to the public headings are still preserved below or in the support files. Notable imported sections: Common Effects, Custom ShaderPass, Combining Multiple Effects, Render to Texture, Multi-Pass Rendering, Performance Tips. ## When to Use This Skill Use this section as the trigger filter. It should make the activation boundary explicit before the operator loads files, runs commands, or opens a pull request. - You need screen-space visual effects in a Three.js render pipeline. - The task involves EffectComposer, bloom, depth of field, color grading, blur, or custom passes. - You are enhancing the final rendered image rather than base scene setup alone. - Use when the request clearly matches the imported source intent: Three.js post-processing - EffectComposer, bloom, DOF, screen effects. Use when adding visual effects, color grading, blur, glow, or creating custom screen-space shaders. - Use when the operator should preserve upstream workflow detail instead of rewriting the process from scratch. - Use when provenance needs to stay visible in the answer, PR, or review packet. ## Operating Table | Situation | Start here | Why it matters | | --- | --- | --- | | First-time use | `metadata.json` | Confirms repository, branch, commit, and imported path through the `external_source` block before touching the copied workflow | | Provenance review | `ORIGIN.md` | Gives reviewers a plain-language audit trail for the imported source | | Workflow execution | `SKILL.md` | Starts with the smallest copied file that materially changes execution | | Supporting context | `SKILL.md` | Adds the next most relevant copied source file without loading the entire package | | Handoff decision | `## Related Skills` | Helps the operator switch to a stronger native skill when the task drifts | ## Workflow This workflow is intentionally editorial and operational at the same time. It keeps the imported source useful to the operator while still satisfying the public intake standards that feed the downstream enhancer flow. 1. EffectComposer (WebGL) - PostProcessing (WebGPU) 2. addPass(new RenderPass(...)) - pass(scene, camera) 3. addPass(new UnrealBloomPass) - bloom(scenePass, ...) 4. composer.render() - postProcessing.render() 5. Chain of passes - Node graph with outputNode 6. GLSL shader passes - TSL node-based effects 7. Confirm the user goal, the scope of the imported workflow, and whether this skill is still the right router for the task. ### Imported Workflow Notes #### Imported: EffectComposer Setup ```javascript import { EffectComposer } from "three/addons/postprocessing/EffectComposer.js"; import { RenderPass } from "three/addons/postprocessing/RenderPass.js"; const composer = new EffectComposer(renderer); // First pass: render scene const renderPass = new RenderPass(scene, camera); composer.addPass(renderPass); // Add more passes... composer.addPass(effectPass); // Last pass should render to screen effectPass.renderToScreen = true; // Default for last pass // Handle resize function onResize() { const width = window.innerWidth; const height = window.innerHeight; camera.aspect = width / height; camera.updateProjectionMatrix(); renderer.setSize(width, height); composer.setSize(width, height); } ``` #### Imported: WebGPU Post-Processing (Three.js r183) The WebGPU renderer uses a node-based `PostProcessing` class instead of `EffectComposer`. Note that `EffectComposer` is **WebGL-only**. ```javascript import * as THREE from "three"; import { pass, bloom, dof } from "three/tsl"; import { WebGPURenderer } from "three/addons/renderers/webgpu/WebGPURenderer.js"; const renderer = new WebGPURenderer({ antialias: true }); await renderer.init(); // Create post-processing const postProcessing = new THREE.PostProcessing(renderer); // Scene pass const scenePass = pass(scene, camera); // Add bloom const bloomPass = bloom(scenePass, 0.5, 0.4, 0.85); // Set output postProcessing.outputNode = bloomPass; // Render renderer.setAnimationLoop(() => { postProcessing.render(); }); ``` ### Key Differences from EffectComposer | EffectComposer (WebGL) | PostProcessing (WebGPU) | | ------------------------------- | -------------------------------- | | `addPass(new RenderPass(...))` | `pass(scene, camera)` | | `addPass(new UnrealBloomPass)` | `bloom(scenePass, ...)` | | `composer.render()` | `postProcessing.render()` | | Chain of passes | Node graph with `outputNode` | | GLSL shader passes | TSL node-based effects | #### Imported: Common Effects ### Bloom (Glow) ```javascript import { UnrealBloomPass } from "three/addons/postprocessing/UnrealBloomPass.js"; const bloomPass = new UnrealBloomPass( new THREE.Vector2(window.innerWidth, window.innerHeight), 1.5, // strength - intensity of glow 0.4, // radius - spread of glow 0.85, // threshold - brightness threshold ); composer.addPass(bloomPass); // Adjust at runtime bloomPass.strength = 2.0; bloomPass.threshold = 0.5; bloomPass.radius = 0.8; ``` ### Selective Bloom Apply bloom only to specific objects. ```javascript import { UnrealBloomPass } from "three/addons/postprocessing/UnrealBloomPass.js"; import { ShaderPass } from "three/addons/postprocessing/ShaderPass.js"; // Layer setup const BLOOM_LAYER = 1; const bloomLayer = new THREE.Layers(); bloomLayer.set(BLOOM_LAYER); // Mark objects to bloom glowingMesh.layers.enable(BLOOM_LAYER); // Dark material for non-blooming objects const darkMaterial = new THREE.MeshBasicMaterial({ color: 0x000000 }); const materials = {}; function darkenNonBloomed(obj) { if (obj.isMesh && !bloomLayer.test(obj.layers)) { materials[obj.uuid] = obj.material; obj.material = darkMaterial; } } function restoreMaterial(obj) { if (materials[obj.uuid]) { obj.material = materials[obj.uuid]; delete materials[obj.uuid]; } } // Custom render loop function render() { // Render bloom pass scene.traverse(darkenNonBloomed); composer.render(); scene.traverse(restoreMaterial); // Render final scene over bloom renderer.render(scene, camera); } ``` ### FXAA (Anti-Aliasing) ```javascript import { ShaderPass } from "three/addons/postprocessing/ShaderPass.js"; import { FXAAShader } from "three/addons/shaders/FXAAShader.js"; const fxaaPass = new ShaderPass(FXAAShader); fxaaPass.material.uniforms["resolution"].value.set( 1 / window.innerWidth, 1 / window.innerHeight, ); composer.addPass(fxaaPass); // Update on resize function onResize() { fxaaPass.material.uniforms["resolution"].value.set( 1 / window.innerWidth, 1 / window.innerHeight, ); } ``` ### SMAA (Better Anti-Aliasing) ```javascript import { SMAAPass } from "three/addons/postprocessing/SMAAPass.js"; const smaaPass = new SMAAPass( window.innerWidth * renderer.getPixelRatio(), window.innerHeight * renderer.getPixelRatio(), ); composer.addPass(smaaPass); ``` ### SSAO (Ambient Occlusion) ```javascript import { SSAOPass } from "three/addons/postprocessing/SSAOPass.js"; const ssaoPass = new SSAOPass( scene, camera, window.innerWidth, window.innerHeight, ); ssaoPass.kernelRadius = 16; ssaoPass.minDistance = 0.005; ssaoPass.maxDistance = 0.1; composer.addPass(ssaoPass); // Output modes ssaoPass.output = SSAOPass.OUTPUT.Default; // SSAOPass.OUTPUT.Default - Final composited output // SSAOPass.OUTPUT.SSAO - Just the AO // SSAOPass.OUTPUT.Blur - Blurred AO // SSAOPass.OUTPUT.Depth - Depth buffer // SSAOPass.OUTPUT.Normal - Normal buffer ``` ### Depth of Field (DOF) ```javascript import { BokehPass } from "three/addons/postprocessing/BokehPass.js"; const bokehPass = new BokehPass(scene, camera, { focus: 10.0, // Focus distance aperture: 0.025, // Aperture (smaller = more DOF) maxblur: 0.01, // Max blur amount }); composer.addPass(bokehPass); // Update focus dynamically bokehPass.uniforms["focus"].value = distanceToTarget; ``` ### Film Grain ```javascript import { FilmPass } from "three/addons/postprocessing/FilmPass.js"; const filmPass = new FilmPass( 0.35, // noise intensity 0.5, // scanline intensity 648, // scanline count false, // grayscale ); composer.addPass(filmPass); ``` ### Vignette ```javascript import { ShaderPass } from "three/addons/postprocessing/ShaderPass.js"; import { VignetteShader } from "three/addons/shaders/VignetteShader.js"; const vignettePass = new ShaderPass(VignetteShader); vignettePass.uniforms["offset"].value = 1.0; // Vignette size vignettePass.uniforms["darkness"].value = 1.0; // Vignette intensity composer.addPass(vignettePass); ``` ### Color Correction ```javascript import { ShaderPass } from "three/addons/postprocessing/ShaderPass.js"; import { ColorCorrectionShader } from "three/addons/shaders/ColorCorrectionShader.js"; const colorPass = new ShaderPass(ColorCorrectionShader); colorPass.uniforms["powRGB"].value = new THREE.Vector3(1.2, 1.2, 1.2); // Power colorPass.uniforms["mulRGB"].value = new THREE.Vector3(1.0, 1.0, 1.0); // Multiply composer.addPass(colorPass); ``` ### Gamma Correction ```javascript import { GammaCorrectionShader } from "three/addons/shaders/GammaCorrectionShader.js"; const gammaPass = new ShaderPass(GammaCorrectionShader); composer.addPass(gammaPass); ``` ### Pixelation ```javascript import { RenderPixelatedPass } from "three/addons/postprocessing/RenderPixelatedPass.js"; const pixelPass = new RenderPixelatedPass(6, scene, camera); // 6 = pixel size composer.addPass(pixelPass); ``` ### Glitch Effect ```javascript import { GlitchPass } from "three/addons/postprocessing/GlitchPass.js"; const glitchPass = new GlitchPass(); glitchPass.goWild = false; // Continuous glitching composer.addPass(glitchPass); ``` ### Halftone ```javascript import { HalftonePass } from "three/addons/postprocessing/HalftonePass.js"; const halftonePass = new HalftonePass(window.innerWidth, window.innerHeight, { shape: 1, // 1 = dot, 2 = ellipse, 3 = line, 4 = square radius: 4, // Dot size rotateR: Math.PI / 12, rotateB: (Math.PI / 12) * 2, rotateG: (Math.PI / 12) * 3, scatter: 0, blending: 1, blendingMode: 1, greyscale: false, }); composer.addPass(halftonePass); ``` ### Outline ```javascript import { OutlinePass } from "three/addons/postprocessing/OutlinePass.js"; const outlinePass = new OutlinePass( new THREE.Vector2(window.innerWidth, window.innerHeight), scene, camera, ); outlinePass.edgeStrength = 3; outlinePass.edgeGlow = 0; outlinePass.edgeThickness = 1; outlinePass.pulsePeriod = 0; outlinePass.visibleEdgeColor.set(0xffffff); outlinePass.hiddenEdgeColor.set(0x190a05); // Select objects to outline outlinePass.selectedObjects = [mesh1, mesh2]; composer.addPass(outlinePass); ``` ## Examples ### Example 1: Ask for the upstream workflow directly ```text Use @threejs-postprocessing to handle . Start from the copied upstream workflow, load only the files that change the outcome, and keep provenance visible in the answer. ``` **Explanation:** This is the safest starting point when the operator needs the imported workflow, but not the entire repository. ### Example 2: Ask for a provenance-grounded review ```text Review @threejs-postprocessing against metadata.json and ORIGIN.md, then explain which copied upstream files you would load first and why. ``` **Explanation:** Use this before review or troubleshooting when you need a precise, auditable explanation of origin and file selection. ### Example 3: Narrow the copied support files before execution ```text Use @threejs-postprocessing for . Load only the copied references, examples, or scripts that change the outcome, and name the files explicitly before proceeding. ``` **Explanation:** This keeps the skill aligned with progressive disclosure instead of loading the whole copied package by default. ### Example 4: Build a reviewer packet ```text Review @threejs-postprocessing using the copied upstream files plus provenance, then summarize any gaps before merge. ``` **Explanation:** This is useful when the PR is waiting for human review and you want a repeatable audit packet. ### Imported Usage Notes #### Imported: Quick Start ```javascript import * as THREE from "three"; import { EffectComposer } from "three/addons/postprocessing/EffectComposer.js"; import { RenderPass } from "three/addons/postprocessing/RenderPass.js"; import { UnrealBloomPass } from "three/addons/postprocessing/UnrealBloomPass.js"; // Setup composer const composer = new EffectComposer(renderer); // Render scene const renderPass = new RenderPass(scene, camera); composer.addPass(renderPass); // Add bloom const bloomPass = new UnrealBloomPass( new THREE.Vector2(window.innerWidth, window.innerHeight), 1.5, // strength 0.4, // radius 0.85, // threshold ); composer.addPass(bloomPass); // Animation loop - use composer instead of renderer function animate() { requestAnimationFrame(animate); composer.render(); // NOT renderer.render() } ``` ## Best Practices Treat the generated public skill as a reviewable packaging layer around the upstream repository. The goal is to keep provenance explicit and load only the copied source material that materially improves execution. - Keep the imported skill grounded in the upstream repository; do not invent steps that the source material cannot support. - Prefer the smallest useful set of support files so the workflow stays auditable and fast to review. - Keep provenance, source commit, and imported file paths visible in notes and PR descriptions. - Point directly at the copied upstream files that justify the workflow instead of relying on generic review boilerplate. - Treat generated examples as scaffolding; adapt them to the concrete task before execution. - Route to a stronger native skill when architecture, debugging, design, or security concerns become dominant. ## Troubleshooting ### Problem: The operator skipped the imported context and answered too generically **Symptoms:** The result ignores the upstream workflow in `plugins/antigravity-awesome-skills-claude/skills/threejs-postprocessing`, fails to mention provenance, or does not use any copied source files at all. **Solution:** Re-open `metadata.json`, `ORIGIN.md`, and the most relevant copied upstream files. Check the `external_source` block first, then restate the provenance before continuing. ### Problem: The imported workflow feels incomplete during review **Symptoms:** Reviewers can see the generated `SKILL.md`, but they cannot quickly tell which references, examples, or scripts matter for the current task. **Solution:** Point at the exact copied references, examples, scripts, or assets that justify the path you took. If the gap is still real, record it in the PR instead of hiding it. ### Problem: The task drifted into a different specialization **Symptoms:** The imported skill starts in the right place, but the work turns into debugging, architecture, design, security, or release orchestration that a native skill handles better. **Solution:** Use the related skills section to hand off deliberately. Keep the imported provenance visible so the next skill inherits the right context instead of starting blind. ## Related Skills - `@00-andruia-consultant` - Use when the work is better handled by that native specialization after this imported skill establishes context. - `@00-andruia-consultant-v2` - Use when the work is better handled by that native specialization after this imported skill establishes context. - `@10-andruia-skill-smith` - Use when the work is better handled by that native specialization after this imported skill establishes context. - `@10-andruia-skill-smith-v2` - Use when the work is better handled by that native specialization after this imported skill establishes context. ## Additional Resources Use this support matrix and the linked files below as the operator packet for this imported skill. They should reflect real copied source material, not generic scaffolding. | Resource family | What it gives the reviewer | Example path | | --- | --- | --- | | `references` | copied reference notes, guides, or background material from upstream | `references/n/a` | | `examples` | worked examples or reusable prompts copied from upstream | `examples/n/a` | | `scripts` | upstream helper scripts that change execution or validation | `scripts/n/a` | | `agents` | routing or delegation notes that are genuinely part of the imported package | `agents/n/a` | | `assets` | supporting assets or schemas copied from the source package | `assets/n/a` | ### Imported Reference Notes #### Imported: Custom ShaderPass Create your own post-processing effects. ```javascript import { ShaderPass } from "three/addons/postprocessing/ShaderPass.js"; const CustomShader = { uniforms: { tDiffuse: { value: null }, // Required: input texture time: { value: 0 }, intensity: { value: 1.0 }, }, vertexShader: ` varying vec2 vUv; void main() { vUv = uv; gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0); } `, fragmentShader: ` uniform sampler2D tDiffuse; uniform float time; uniform float intensity; varying vec2 vUv; void main() { vec2 uv = vUv; // Wave distortion uv.x += sin(uv.y * 10.0 + time) * 0.01 * intensity; vec4 color = texture2D(tDiffuse, uv); gl_FragColor = color; } `, }; const customPass = new ShaderPass(CustomShader); composer.addPass(customPass); // Update in animation loop customPass.uniforms.time.value = clock.getElapsedTime(); ``` ### Invert Colors Shader ```javascript const InvertShader = { uniforms: { tDiffuse: { value: null }, }, vertexShader: ` varying vec2 vUv; void main() { vUv = uv; gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0); } `, fragmentShader: ` uniform sampler2D tDiffuse; varying vec2 vUv; void main() { vec4 color = texture2D(tDiffuse, vUv); gl_FragColor = vec4(1.0 - color.rgb, color.a); } `, }; ``` ### Chromatic Aberration ```javascript const ChromaticAberrationShader = { uniforms: { tDiffuse: { value: null }, amount: { value: 0.005 }, }, vertexShader: ` varying vec2 vUv; void main() { vUv = uv; gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0); } `, fragmentShader: ` uniform sampler2D tDiffuse; uniform float amount; varying vec2 vUv; void main() { vec2 dir = vUv - 0.5; float dist = length(dir); float r = texture2D(tDiffuse, vUv - dir * amount * dist).r; float g = texture2D(tDiffuse, vUv).g; float b = texture2D(tDiffuse, vUv + dir * amount * dist).b; gl_FragColor = vec4(r, g, b, 1.0); } `, }; ``` #### Imported: Combining Multiple Effects ```javascript import { EffectComposer } from "three/addons/postprocessing/EffectComposer.js"; import { RenderPass } from "three/addons/postprocessing/RenderPass.js"; import { UnrealBloomPass } from "three/addons/postprocessing/UnrealBloomPass.js"; import { ShaderPass } from "three/addons/postprocessing/ShaderPass.js"; import { FXAAShader } from "three/addons/shaders/FXAAShader.js"; import { VignetteShader } from "three/addons/shaders/VignetteShader.js"; import { GammaCorrectionShader } from "three/addons/shaders/GammaCorrectionShader.js"; const composer = new EffectComposer(renderer); // 1. Render scene composer.addPass(new RenderPass(scene, camera)); // 2. Bloom const bloomPass = new UnrealBloomPass( new THREE.Vector2(window.innerWidth, window.innerHeight), 0.5, 0.4, 0.85, ); composer.addPass(bloomPass); // 3. Vignette const vignettePass = new ShaderPass(VignetteShader); vignettePass.uniforms["offset"].value = 0.95; vignettePass.uniforms["darkness"].value = 1.0; composer.addPass(vignettePass); // 4. Gamma correction composer.addPass(new ShaderPass(GammaCorrectionShader)); // 5. Anti-aliasing (always last before output) const fxaaPass = new ShaderPass(FXAAShader); fxaaPass.uniforms["resolution"].value.set( 1 / window.innerWidth, 1 / window.innerHeight, ); composer.addPass(fxaaPass); ``` #### Imported: Render to Texture ```javascript // Create render target const renderTarget = new THREE.WebGLRenderTarget(512, 512); // Render scene to target renderer.setRenderTarget(renderTarget); renderer.render(scene, camera); renderer.setRenderTarget(null); // Use texture const texture = renderTarget.texture; otherMaterial.map = texture; ``` #### Imported: Multi-Pass Rendering ```javascript // Multiple composers for different scenes/layers const bgComposer = new EffectComposer(renderer); bgComposer.addPass(new RenderPass(bgScene, camera)); const fgComposer = new EffectComposer(renderer); fgComposer.addPass(new RenderPass(fgScene, camera)); fgComposer.addPass(bloomPass); // Combine in render loop function animate() { // Render background without clearing renderer.autoClear = false; renderer.clear(); bgComposer.render(); // Render foreground over it renderer.clearDepth(); fgComposer.render(); } ``` #### Imported: Performance Tips 1. **Limit passes**: Each pass adds a full-screen render 2. **Lower resolution**: Use smaller render targets for blur passes 3. **Disable unused effects**: Toggle passes on/off 4. **Use FXAA over MSAA**: Less expensive anti-aliasing 5. **Profile with DevTools**: Check GPU usage ```javascript // Disable pass bloomPass.enabled = false; // Reduce bloom resolution const bloomPass = new UnrealBloomPass( new THREE.Vector2(window.innerWidth / 2, window.innerHeight / 2), strength, radius, threshold, ); // Only apply effects in high-performance scenarios const isMobile = /iPhone|iPad|Android/i.test(navigator.userAgent); if (!isMobile) { composer.addPass(expensivePass); } ``` #### Imported: Handle Resize ```javascript function onWindowResize() { const width = window.innerWidth; const height = window.innerHeight; const pixelRatio = renderer.getPixelRatio(); camera.aspect = width / height; camera.updateProjectionMatrix(); renderer.setSize(width, height); composer.setSize(width, height); // Update pass-specific resolutions if (fxaaPass) { fxaaPass.material.uniforms["resolution"].value.set( 1 / (width * pixelRatio), 1 / (height * pixelRatio), ); } if (bloomPass) { bloomPass.resolution.set(width, height); } } window.addEventListener("resize", onWindowResize); ``` #### Imported: See Also - `threejs-shaders` - Custom shader development - `threejs-textures` - Render targets - `threejs-fundamentals` - Renderer setup #### Imported: Limitations - Use this skill only when the task clearly matches the scope described above. - Do not treat the output as a substitute for environment-specific validation, testing, or expert review. - Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.