The Violinist: Houdini to Unreal Pipeline

CURRENT PROJECTSSENIOR THESIS: "THE VIOLINIST"

1/9/20241 min read

Collaboration Partner:

Emma Schaberg: https://www.emmaschaberg.website

Current Visualization (Previs):

Outsourced FX Consultant:

Kyle Lin: https://kylelinvfx.com

Houdini to Unreal Using VAT (Vertex Animation Textures

One of the issues that Emma and I had run into while rendering our updated previs, is the heavy load that the Niagara system emitter causes. Not only does it slows down both the file and the render time, but it makes it nearly impossible to navigate and work in. I needed to find a better way to optimize the particles to improve efficiency.

I worked with Kyle Lin, found at https://kylelinvfx.com , to establish a working pipeline by using VAT instead of a Niagra Particle System Emitter. Kyle was able to document a working process:

We found this installing tutorial catered to particle import:

Completed test with the particle pscale attribute

VAT PARTICLE TUTORIAL DOCUMENTATION

Written out by Kyle Lin:

During testing the pipeline for the streamline particles, we had a couple issues.

First, It could not render properly because there were too many particles. Depending on the amount of particles, you have to change your Target Texture Width accordingly. So instead of the default 1024, we had to upres it to 4k, 4096.

Second, there was an issue that caused the texture to be flat. We detected that it was a SideFX Labs installation error and once we reinstalled, then it worked.

Houdini to Unreal Testing:

Simplified Pipeline (Primarily used and subject to change):

  1. Clean up geometry so abc will be reasonably sized

    • Cache Geometry

    • Delete Attributes except P, Cd, uv

    • Change the uniform scale to 100, and P.X to 90

  1. Cache as an alembic file

  2. Set up unreal project (If needed)

  3. Import as Geometry Cache

    • Offset to check animation

  4. In new sequencer

    1. - Add ABC output into the sequence list

    2. Add new track as geometry cache

  5. Texture and light

  6. Render

Resources used:

Test Render with pipeline:

Houdini to Unreal Resources

Side-FX Documentation on Houdini-Niagra Plugin:

https://www.sidefx.com/docs/houdini/unreal/niagara.html

Github Houdini-Niagra Plugin:

https://github.com/sideeffects/HoudiniNiagara/releases

Smoke sourcing particles (Controlled):