Course Overview

Please note: This class is currently being edited into small clips and will replace the raw footage that is currently available for viewing.

Class Description:

“Velocity Forces 2.0: Advanced” is an in-depth class expanding on “ Velocity Forces 1.0”. It delves deeper into creating velocity fields, exploring the differences between Houdini Standard Volumes and OpenVDB volumes.

The course focuses on techniques to help you refine velocity fields, blend multiple fields together, and use alternative simulation outputs for unique movement. You'll learn how to create vorticles, enhance simulations with wake turbulence forces, as well as injecting extra detailed motion into low-resolution smoke sims. Additionally, this class will cover volume optical flow fields on both 2D planar and 3D geometry, plus utilizing the Potential Flow node for 3D surface advection.

This class will also show how to move beyond volume-based fields into dynamic VEX coding, reducing the volume caching overhead, while also tackling advanced mathematical concepts, from matrices and quaternions to cross products and vector math.

Learning Outcomes:

Students will walk away with a more complete understanding of volumes in Houdini, advanced VEX computations, and how to utilize powerful native nodes to generate more intricate motion in their simulations.

Course curriculum

  1. Resources

  2. Session 1

  3. Session 2

  4. Session 3

About this course

  • $150.00
  • 8 lessons
  • 9 hours of video content

Course Teaser

Session 1

Volumes, Volumes, Volumes!

Dive into a better understanding of the volumetric formats available, their pros and cons, how to make them from scratch, masking them, blending them, and generating them from sim data.
  1. Volumes Illustrated
    1. Houdini Standard Volumes
    2. OpenVDB volumes
    3. VDB Tree Structure
  2. References
    1. density field
    2. vel field
  3. Field Masking
    1. Add, Subtract, Multiply
    2. Dealing with “Jaggies” / Stepping
  4. Velocity Fields From Sim Data
    1. Cloth driven POPs
    2. Pyro driven Threads

Session 2

Round and round we go!

Blend two distinctly unique vel fields to generate a single vel field, and explore how to build and implement vorticle influence into your sims.
  1. Field Blending
    1. Blend various VEX/VOP fields
  2. Vorticles
    1. Intro, and references
    2. POP static
      1. Concepts
      2. Orientation vectors
    3. POP randomized orientation
      1. Seed generation
      2. Extracting vectors from orientation
    4. POP randomized continuous rotation
      1. Defining  stable seed rotations
    5. POP randomized translation
      1. Seed orientation on surface while moving
    6. Sim Examples
      1. RBD Wooden fencing
      2. FLIP Muddy swirls
      3. Vellum shredded cloth
      4. Vellum hair blown
      5. Pyro Wake Turbulence
    7. Gas Vorticle Forces node

Session 3

Stay close!

Wield Optical Flow data into driving surface movement, and learn how to generate and confine motion to surfaces. Also see how it’s possible to deform volumetrics post sim.
  1. Optical Flow
    1. Concepts
    2. Volume Optical Flow 2D planar & 3D surfaces
    3. Sim Examples
      1. FLIP water
      2. Vellum grains
      3. Vellum cloth
      4. Pyro smoke
  2. Surface Flows
    1. Intro
    2. VDB Potential Flow node
    3. Gradient fields
    4. Extracting vel from color
  3. Post Pyro Deformation


David Torno

Visual Effects Professional

David Torno is a self-taught visual effects professional with a passion for the technical and educational side of VFX. Since beginning his career in 2000, he has worked on films, commercials, music videos, and large-scale multimedia projects. In 2008 he started sharing his wealth of knowledge with other creatives through video tutorials, project templates, and utility scripts. In recent years David has focused mostly on 3D volumetric and particle animation. Through the consolidation of his life's work under the Fendra Fx name, David continues to create helpful tools, and informative training videos for the creative community.



  1. Houdini 19.5 or newer (class will be taught with H20)
  2. Comfortable with writing VEX code (all code is fully explained in class)
  3. Velocity Forces 1.0 class is a prerequisite (2.0 builds upon techniques and information from 1.0 course)
  4. Computer (Please see SideFx system requirements)
    2. A second Monitor is recommended, but not necessary
  5. Houdini (Apprentice License is free)


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Multi-Session Courses
Students may request a refund up to 1 day before the start of the course. Students may also withdraw from Multi-Session Courses at any time and are entitled to a pro-rated refund. The withdrawal date must be 1 day before the next class they intend to drop.

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Please send a request to drop a class via email to [email protected].
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  1. Student’s full name
  2. Name of the course(s) being dropped

See you in Class!