The USB
Paradox.

Overview

I was approached by Clemens Willberger to assist during the Research & Development phase. My work focused on creating and refining key visual effects — lightning strikes, water droplets, and volumetric lighting — giving the compositing team a versatile toolkit to work with.

Film Still 1

USB Paradox · 2024

Film Still 2

USB Paradox · 2024

Film Still 3

USB Paradox · 2024

Film Still 4

USB Paradox · 2024

Film Still 5

USB Paradox · 2024

Film Still 6

USB Paradox · 2024

Process

My role was not to create the final image but to build efficient workflows and reusable assets that could accelerate production — spanning water droplet rendering, lightning generation, volumetric dome lighting, HDRIs and cloud assets.

Starting with a fully rendered approach in KarmaXPU, I discovered that simulating it in Nuke via displacement offered significantly more control — and near-realtime feedback.

Starting from a point cloud architecture, I progressively added branching, twitching, and multi-path switching — delivering over 40 variations to the team.

Point Cloud & Shortest Path

Houdini · R&D

1

Lightning forms when electrical discharge follows the path of least resistance through the air. Using a shortest-path algorithm allows multiple lightning branches to rapidly propagate between regions of high voltage, creating the characteristic streaking patterns.

Geometry Light Test

KarmaXPU · R&D

2

Early test to see if we could render the lightning geometry as a geometry light. This resolved very slow though and in subsequent tests I switched to rendering the lightning with instanced pointlights.

Instanced Point Light Render

KarmaXPU · R&D

3

Early test to see if we could render the lightning geometry as a geometry light. This resolved very slow though and in subsequent tests I switched to rendering the lightning with instanced pointlights.

Video

Animated Lightning Strikes

KarmaXPU · Rendering

4

First animated output of the lightning strikes achieved by carving the shortest path links and changing the end point seed slightly. Rendered with instanced point lights in KarmaXPU. This version was more of a proof of concept to show that we could achieve the desired look and performance, but the rendering took more time than we wanted.

Video

Branching & Flicker v03

Houdini · FX

5

I added more visual interest to the lightning by introducing more branching and flickering. Branching was achieved by randomly splitting the shortest path links at certain intervals, creating a more natural and chaotic lightning pattern. Flickering was implemented by randomly varying the intensity of the instanced point lights over time.

Video

Volume + Light AOV Separation

KarmaXPU & Nuke · Rendering & Compositing

6

To give the compositing team more control over the lightning, I separated the volume and light AOVs in render. This would become especially useful for shots where the lightning needs to interact with the clouds and environment, allowing for more flexibility in comp.

A rather small but important part was to figure out how to get the spotlights in front of the spaceship to light the clouds and environment without causing too much noise in render. I experimented with different sampling techniques and found that using uniform sampling for the direct lighting of the volumetric environment, gave me the best results in terms of quality and performance. Of course rendering this out as an additional AOV pass would yield the biggest benefit for the compositing

I built a set of clouds and HDRIs & HDR Images deployable at any angle to serve all the different shots. More organic foreground clouds were sourced from the VRAY library.

HDR Still 1

KarmaXPU · Rendering

HDR Still 2

KarmaXPU · Rendering

HDRI Bright Top Light

KarmaXPU · Rendering

HDRI Dark Stormy Environment

KarmaXPU · Lookdev

Complete
Breakdown.

The complete breakdown covers the full scope of production — rendering, compositing, lighting, modeling and the combined effort of the entire team.

Learnings

Key technical skills developed and deepened over the course of the R&D process.