A coding-agent guide for SideFX Houdini, a 3D application for visual effects, procedural modeling, animation, simulation, and rendering. It covers Houdini’s Python and VEX scripting, USD scene workflows, render setup, and task-graph processing.

Use it to script Houdini with Python or VEX, build geometry and simulations, manage USD scenes and Karma renders, and schedule procedural processing with PDG or TOPs.

It helps automate complex effects and production pipelines, troubleshoot simulations and procedural networks, and run repeatable jobs outside the interactive application.

houdini — Skill for Claude Code by alivirgo

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add alivirgo/Major-AI-Skills --skill houdini

Clone the repo

git clone --depth 1 https://github.com/alivirgo/Major-AI-Skills

Made for: Claude Code.

Or install mas-3d-games, the plugin that ships this one along with the rest of its 8 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/alivirgo/major-ai-skills/houdini/github.svg)](https://agentmods.dev/skills/alivirgo/major-ai-skills/houdini)

Your own site

<a href="https://agentmods.dev/skills/alivirgo/major-ai-skills/houdini"><img src="https://agentmods.dev/badge/skills/alivirgo/major-ai-skills/houdini/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/alivirgo/major-ai-skills/houdini"><img src="https://agentmods.dev/badge/skills/alivirgo/major-ai-skills/houdini.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 30 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,107 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00030	$0.02107
Opus 5	$0.00015	$0.01053
Sonnet 5	$0.00006	$0.00421
Haiku 4.5	$0.00003	$0.00211

Measured today against content hash 6529c45568f5, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

houdini scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured today.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

Use this snippet in a **Point Wrangle** SOP to orient instanced particles along a curl noise velocity vector:

plugins/mas-3d-games/skills/houdini/SKILL.md · 170 lines

How it starts

The opening of the file, as written. The whole thing — 170 lines — stays where its author put it; the contents beside it link to each section on GitHub.

SideFX Houdini AI Skill Guide (Claude)

Overview & Engine Architecture

SideFX Houdini is the industry-standard procedural VFX, procedural modeling, dynamic simulation, and USD-native pipeline tool. Claude operates as a Senior Houdini TD (Technical Director), specializing in VEX syntax and vector math, Python hou scripting via hython, Solaris USD / Karma XPU rendering, PDG/TOPs task-graph automation, and headless CLI simulation baking.

Houdini Context Architecture & Execution Pipeline

┌─────────────────────────────────────────────────────────────┐
│                 Houdini Context Architecture                │
│                                                             │
│  Context Domains                                            │
│  ├── SOPs (Surface Operators - Geometry & Modeling)         │
│  ├── DOPs (Dynamic Operators - FLIP, Pyro, Vellum, RBD)     │
│  ├── LOPs / Solaris (USD Scene Composition & Lighting)      │
│  ├── TOPs / PDG (Procedural Dependency Graph & Wedging)     │
│  └── Karma XPU (Hydra Delegate CPU/GPU Renderer)            │
│                                                             │
│  Programming & Scripting Interfaces                         │
│  ├── VEX (High-Performance SIMD Vector Expression Language) │
│  ├── `hou` (Python 3.11 Houdini Object Model API)           │
│  └── Hython / HBatch (Headless Batch Execution Interpreters)│
└─────────────────────────────────────────────────────────────┘

Operational Capabilities & Agent Directives

VEX Code Generation & Optimization: Write vectorized, thread-safe VEX snippets for Attribute Wranglers, Volume Wranglers, and Point Deformation routines using @P, @v, @orient, and @pscale.
Headless Python Automation (hython): Script standalone pipeline tools using hou to inspect scenes, dirty/cook TOP networks, parameterize HDAs, and trigger ROP nodes.
Simulation Solver Tuning: Troubleshoot substepping, collision margins, pressure projection convergence, and spatial oversampling in Vellum, FLIP, and RBD solvers.
Solaris & MaterialX USD Pipeline: Construct USD primitive hierarchies, configure Karma XPU shaders using MaterialX (mtlxstandard_surface), and set up AOV cryptomatte passes.

Read the full file on GitHub · 170 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

today Changed · -16 tokens per session 6529c45568f5
12d ago First seen · 170 lines · 46 tokens per session scan A 7874341db556

Subscribe to this mod's changes

houdini is a skill published in the GitHub repository alivirgo/Major-AI-Skills (1 stars, last pushed today), licensed MIT. It adds 30 tokens to every session and 2,107 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

3d Creative and media agent-skills agentic-skills ai-agent-skills ai-agents flip-fluids hou-python houdini pdg-tops solaris-karma vellum vex

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houdini