Vector Field Instancing

Inspired by: Okamirufu Vizualizer

Create a dense, swirling 3D field where millions of individual points follow a fluid-like path. This is the foundation of many generative art “vortex” effects.

Operator Families in this Recipe

• POPs (Point Operators): Creating and animating the vector field.
• SOPs (Surface Operators): The base geometry for instancing.
• COMPs (Components): Managing the 3D scene and rendering.

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Part 1: High-Density 3D Grid

1. The Container: Create a Geo COMP and enter it.
2. The POP Bridge: Create a POP SOP. Double-click to enter the POP network.
3. The Base: Add a Grid POP.
   • Size → 5, 5, 5.
   • Rows/Columns/Layers → 50, 50, 50. This creates 125,000 base points.
4. The Force Field: Add a Noise POP.
   • Output Tab → Set “Output” to Offset Position or Velocity.
   • Noise Tab → Set “Monochrome” to Off. This generates unique X, Y, and Z vectors for each point.
   • Amplitude → 0.5.
   • Period → 2.0.
5. The Motion: Animate the Transform (Translate Z) of the Noise POP using absTime.seconds * 0.1 to make the field “flow” over time.

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Part 2: Instancing Tiny Geometry

Instead of rendering simple points, we can instance 3D geometry onto every point in the field.

1. The Instance Source: Connect your POP SOP to the Instancing Tab of your Geo COMP.
2. The Shape: Create a Sphere SOP (set to “Mesh” and low frequency) or a small Box SOP.
3. Enable Instancing: Turn on “Instancing” in the Geo COMP.
   • Translate X/Y/Z → Use the P(0), P(1), and P(2) attributes from the POP SOP.
   • Scale X/Y/Z → Map to the Noise POP’s output to make instances shrink and grow as they move.

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Part 3: Shading & Lighting

1. Apply a Constant MAT or a PBR MAT to the Geo COMP.
2. Point Coloring: In the POP network, add an Attribute POP to set the Cd (Color) attribute based on the point’s velocity. This makes fast-moving particles glow brighter.
3. The Look: Combine this with the Post-Processing Recipe for a high-end generative aesthetic.

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Part 4: Interactive Control

• Connect an Audio File In CHOP to the Noise POP’s Amplitude.
• Now, the entire field will “pulse” or “vibrate” in sync with the beat, creating a powerful audio-visual experience.

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Parameter Tuning & Behavior

Parameter	Behavior
Grid Divisions	Higher = more dense vortex (very high counts require GPU instancing); Lower = sparse field.
Noise Amplitude	Higher = more violent, wide-sweeping swirls; Lower = tight, subtle movement.
Noise Period	Higher = larger, lazier “wind” patterns; Lower = small, chaotic, “jittery” eddies.
Noise Speed	Higher = faster evolution of the field; Lower = slow, hypnotic flow.
Audio Sensitivity	Higher = field “vibrates” more intensely to sound; Lower = subtle, rhythmic pulsing.

Network Architecture

To visualize how the data flows, here is a map of the final network:

[ POP NETWORK ]
Grid POP (50x50x50)
      │
      ▼
Noise POP (Vector Mode: Offset Pos)
      │
      ▼
Attribute POP (Velocity to Color)
      │
      ▼
[ POP SOP ] ───────┐
                   │ (Data Source)
                   ▼
[ Sphere SOP ] ──▶ [ Geo COMP ] ───▶ [ Render TOP ]
                   (Instancing On)

📚 Learning Path · Stage 8 - Advanced Projects · step 43 of 44

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