Networks
Understanding Houdini's network system
What are Networks?
Networks are Houdini’s node graphs. Data flows from one node to the next, top to bottom, and each network works on a specific type of data (geometry, simulation, shaders, etc.). You build results by wiring nodes together, adjusting parameters, and organizing related steps into groups.
Key ideas
- • One network per context (SOPs for geometry, DOPs for dynamics, etc.)
- • Wires pass data from output ports to input ports
- • Results update live as you change parameters
- • Group complex parts into sub-networks to stay organized
Network Types
| Network | Path Prefix | Purpose | Examples |
|---|---|---|---|
| SOP | /obj/geo1/ | Geometry operations | Box, Subdivide, Noise, Boolean |
| DOP | /obj/dopnet1/ | Dynamic simulations | RBD Solver, Fluid, Particles |
| VOP | /mat/ | Shader networks | Materials, Textures, Shaders |
| ROP | /out/ | Render & export | Mantra, FBX Export, Alembic |
| CHOP | /ch/ | Channel operations | Animation, Audio, Motion |
| TOP | /tasks/ | Task operations | PDG, Wedging, Batch Processing |
SOP Networks (Most Common)
Surface Operators (SOPs) are where most geometry work happens. Think of it as a conveyor belt: you create something, tweak it, and pass it along. Keep graphs tidy, name nodes clearly, and use Nulls to mark milestones.
Create
- • Box, Sphere, Grid
- • Curve, Line
- • File (import)
Modify
- • Transform, Scale
- • Subdivide, Smooth
- • Noise, Deform
Combine
- • Boolean, Merge
- • Copy to Points
- • For Each, Loop
Sub‑Networks
Sub‑networks are folders inside your graph. Use them to group related steps, hide complexity, and reuse setups. Name subnetworks clearly and expose only the controls you need on the outside.
- • Group complex sections to keep the main graph readable
- • Promote key parameters to the sub‑network interface
- • Use breadcrumbs and “U/I” to move up/down between levels
Navigation Tips
Essential Shortcuts
- •
Tab— Create node menu - •
U— Go up one network level - •
I— Dive into selected node - •
G— Open geometry spreadsheet
Best Practices
- • Use Null nodes for organization and outputs
- • Name nodes descriptively
- • Group related operations in sub‑networks
- • Keep networks flowing top to bottom