Procedural Fish Animation in Blender 3.0 Geometrynodes!

Overview

This tutorial shows how to build a fully procedural, Geometry Nodes–based fish animation in Blender 3.0 that continues to evolve “until the end of time.” The motion is driven by time/frame math rather than manual keyframes. The author also covers practical tips for:

• Controlling movement direction
• Ensuring rotation correctness
• Adding a final wobble/wave effect for more believable swimming

The animation is primarily non-looping by default, relying on time progression rather than a looping setup.

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Key Workflow / Node Ideas (Technology & Features)

1) Start with a clean setup

• Begin with a clean scene
• Use one Geometry Nodes position/position-like basis from the fish model

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2) Procedural displacement via noise over time

• Use a Noise Texture (1D) setup
• Drive its movement by offsetting with time
• Increase displacement amplitude using:
  • Vector Math → Scale
  • Example scale around 10
• Recenter displacement so the fish doesn’t drift:
  • Use Subtract
  • Example subtract around 2.5

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3) Time-driven animation (no manual animation)

• Use a Value/Math approach with #frame as a temporary stand-in for a future Scene Time input
• Drive progression using Math → Divide to set speed, with examples such as dividing by 24, later adjusted (e.g., 50)
• Notes on looping:
  • The effect is non-looping by default
  • To loop, you’d need to copy the entire node setup and add extra math (not taught in the tutorial)

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4) Directional timing: head leads, fins lag

• Compute distance from origin using a Distance node
• Use that distance as a factor, experimenting with multiply/divide adjustments (e.g., dividing around 20)
• Negative scaling may be tried (example: -50) to achieve the desired timing:
  • Head moves first
  • Fins move later

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5) Rotation alignment to movement direction

• Reuse the noise/time section to estimate a future position, so the fish can face where it’s effectively moving
• Convert computed direction into rotation using:
  • Utilities → Align Euler to Vector
• Apply the rotation with Vector Rotate (Euler mode), ensuring the wiring order is correct:
  • Position happens first
  • Offset happens second
• Fix twisting / wonky orientation by tuning rotation parameters:
  • Set pivot to Z (helps prevent upside-down twisting / wrong axis behavior)
  • Optionally adjust an Add node offset (example: 0.3)
  • Further tune with divide/scale changes (examples: divide 10, then 20, scale around 15)

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6) Add a wave/wobble for propulsion feel

• Create a sine-based wave using:
  • Time → Sine (Math/Sine node)
• Apply the wave to rotation using:
  • Utilities → Rotate Euler
  • Use the Z axis
  • Use Object → Local so rotation behaves consistently with orientation
• Tune intensity/influence with Multiply nodes, with example values such as:
  • 0.5
  • stronger settings like 50
  • smaller influence like 0.1
• Use reroutes to keep the node graph organized

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7) Pattern variability

• If the movement doesn’t look right, change the noise/randomness parameters
• Example approach:
  • Add another Add node with values like 500 to generate a new procedural pattern

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Deliverables / Extras

• The author mentions a complete fish model + node file (including caustics) is available on their Gumroad account (link referenced in description/comments).
• The tutorial also includes typical promotion calls (e.g., Twitter and like/subscribe).

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Main Sources / Speakers (from the subtitles)

• The primary speaker is the tutorial author, speaking throughout.
• No additional named sources appear beyond:
  • the author’s Gumroad/Twitter
  • the Blender Geometry Nodes feature set