Houdini 20.5 - USD & LOPS Creating a Chocolate Advert

In this tutorial series 01-05, we build a fake chocolate egg commercial from scratch using Houdini’s USD-based LOPs workflow. Each step represents a key department in a modern VFX pipeline. ASSETS, LAYOUT ,ANIM, FX & LIGHTING

🥚 Tutorial Overview • Project: Fake social media advert for a chocolate egg. • Focus: Workflow using Houdini LOPs & USD in a single scene, split into department-style networks. • Goal: Simulate a VFX pipeline (01 ASSETS → 02 LAYOUT → 03 ANIM → 04 FX → 05 LIGHTING).

🛠️ ASSETS 01

• Created a procedural chocolate egg model (unbroken, fractured, open, with/without liquid).

• Used Component Builder to structure variants and assign purposes (proxy/render).

• Procedural texture with Caponicus for height map/displacement.

• Assigned MaterialX shaders for milk/white chocolate and caramel.

• Implemented versioning and structured path-based exports.

🎨 Lookdev Stage

• Live-link procedural height maps into MaterialX shaders.

• Shader displacement controlled by attributes.

• Multi-material support with switching between chocolate variants.

🎥 LAYOUT 02

• Build a USD structure: Cameras, geometry, lights.

• Added 3 named cameras with shot switching via Shot Edit.

• Set basic render resolution (e.g., 1280x720) and FPS.

• Brought in egg variants, backdrop, and assigned layout-level variants.

🏃 ANIM 03

• Imported layout into new LOPs network.

• Animated egg opening via visibility/pruning and SOP-based animation.

• One shared animation used across three shots.

💥 FX 04

• Imported animated shot.

• Added fluid sim for caramel using Houdini FLIP.

• Used proxy geometry for fast previews.

💡 LIGHTING 05

• Imported live layout, animation, and FX.

• Added light rigs and environment lights.

• Spinning light and object setups for quick lookdev previews.

• Configurable AOVs, render passes, and Karma XPU settings.

🔄 Automation & TOPs

• Created turntables for variants using expressions (spinning asset or lights).

• Used TOPs to render multiple variants (milk vs. white chocolate) automatically.

• Substituted render settings (high/low/very low quality) using switch nodes.

• Saved to structured paths with $OS, $VARIANT, and versioning.

🗃️ Project Management • All USD work done in one scene file.

• Each department isolated in its own LOP network.

• Modular setup to enable clean asset handoff or self-iteration.

• Proxy and render purposes split for optimized previews and final output.