Houdini SOP Geometry Basics for FX Sources (beginner guide)

Build the source geometry every simulation needs. The point of this stage is not modeling — it is producing clean, attribute-rich geometry to feed into DOPs. Here’s how to do it in Houdini on macOS, step by step — part of the free Houdini beginner curriculum.

Lesson 2 of the Houdini curriculum. Next up: Pyro — Fire and Smoke.

What you’ll do

• Drop primitive geometry from Tab menu: Box, Sphere, Tube, Grid, Curve
• Use Transform, Copy to Points, Scatter, and Group SOPs as utility nodes
• Understand the point / vertex / primitive distinction in Houdini — points are positions, vertices are uses of points by primitives, primitives are polys or other geometry types
• Inspect attributes with the Geometry Spreadsheet pane (open with Geometry Spreadsheet from the pane tab menu) and the MMB info popup on a node
• Add attributes with Attribute Wrangle (a single VEX expression like @temperature = 300;) or Attribute Create — only enough to feed FX sources
• Use a Null SOP as a labeled bookmark node — common convention: OUT_render, OUT_collide, OUT_emit
• Use File Cache SOP to write cached geometry to $HIP/geo/ and reload it instantly — the foundation of fast iteration
• Recognize the error (red border) and warning (yellow border) indicators on nodes, and read the message in the Parameter Editor

Do it hands-free with Skilly

Reading steps is one thing; doing them while the menus are in front of you is another. Skilly is a voice-first tutor for macOS: you ask out loud — “where’s the sop panel?” — and it answers while moving your cursor to the exact button, watching your actual Houdini window. It’s the same Houdini curriculum these lessons come from, taught live instead of read. Free to start.

Keep going

This is one stage of the full Houdini beginner curriculum. Continue with Pyro — Fire and Smoke.