Overview

A 3D Gaussian Splatting web viewer for an end-to-end asset-pipeline showcase. The same garden was authored conventionally in Houdini and Unreal, captured at a multi-camera rig, reconstructed back to 3D via COLMAP, trained in parallel by Postshot and Lichtfeld Studio, then served as a single-page web experience powered by Spark on Three.js. Three million Gaussian splats, real-time interactive FX, hand-tracking input, and a 3DGS / USD layer switcher for inspecting alternative representations of the same scene.

The viewer surfaces the pipeline itself as the artefact. Visitors can flip between the splat render and two alternative USD-PointInstancer representations (Billboard and Voxel) of the same scene, and a tech-spec drawer walks through each asset's authoring history with embedded videos and before/after comparisons.

The same garden assets were also deployed in a parallel Virtual Production track — driven through MediaPipe hand-tracking and pushed to an LED Wall via disguise — making this a dual-medium showcase rather than a single deliverable.

Pipeline

Five stages, end-to-end — from conventional DCC authoring to a live splat in the browser. Two Gaussian-Splatting trainers were run in parallel for cross-comparison.

Houdini Procedural Tools

Grape Hyacinth — Per-part GUI

Authored a procedural grape-hyacinth tool in Houdini with a per-part GUI — artists tune stalk count, bloom density, petal twist. Animation is baked to a Vertex Animation Texture for GPU-cheap playback in Unreal, then scattered via PCG so density follows the planter splines. Hero render uses Unreal's SubsurfaceTwoSidedFoliage shader so backlit petals translucently glow without doubling the geometry. SSS colour and falloff were tuned against the Shot 4B lighting setup.

Houdini procedural tool with per-part GUI.

Final stylised render — VAT in Unreal, PCG scatter, Movie Render Queue.

Vine Generator

Built a vine generator to procedurally create growth patterns that wrap around scene geometry, giving the team a flexible way to drape vines on architecture and props without bespoke modelling per surface. Pairs in Unreal with a UMG-driven world-position-offset shader for procedural growth synchronised to the camera move.

Vine growth animation tied to the Shot 4B interaction beat.

3DGS Capture, Cleanup & Validation

Beyond browser-side playback, the same Gaussian-Splatting assets were captured out of Unreal and validated against the source geometry to surface drift, holes, and alignment issues before relying on the splat downstream.

Pointcloud Overlay Validation

Loaded the trained 3DGS asset alongside its source pointcloud and used an XYZ-tool overlay to compare both representations side-by-side. This catches reconstruction errors that aren't visible from a single viewpoint — drift along occluded faces, holes where coverage was thin, alignment skew from camera-pose error.

Cleanup via GSOPs DBSCAN

Cleaned the trained splat using a USD-voxel pass to isolate clean regions, followed by DBSCAN clustering through a Houdini GSOP workflow to remove stray outlier splats that survived training. The cleanup pass measurably improved the splat's edge density without sacrificing the photographic detail in the interior.

 

Trained 3DGS for the Shot 4B map — cleaned and overlaid for validation.

Real-time Web Viewer

The viewer ships as a single-page web app — Spark for splat rendering on top of Three.js, GitHub Pages for hosting, no install. A scripted opening camera move (FBX-driven) introduces the scene, then orbit / WASD / hand-tracking takes over for free exploration.

Parallel Track — Virtual Production

The same garden assets ran through a parallel Virtual Production deployment — hand-tracking driving in-engine interaction, splats sitting alongside conventional geometry inside Unreal, and the whole composition pushed to an LED Wall via disguise. Both the browser viewer and the VP shoot share the same source pipeline; only the playback medium differs.

MediaPipe → Unreal Interaction

Built the MediaPipe-to-Unreal pipeline as the interaction backbone. Key fixes that took the prototype from "twitchy demo" to "shoot-ready": lerp smoothing on the gesture-driven values to kill jitter from the per-frame MediaPipe callbacks, and a previous-state persistence fix so plant growth retains its state when hands leave the frame instead of snapping back to zero.

MediaPipe-driven daffodil interaction with lerp smoothing and state persistence.

Statue VAT — Hand-driven Animation

Added a statue interaction using Vertex Animation Textures driven by MediaPipe input, so hand-tracked gestures can trigger and scrub the statue animation in engine. Two-handed setup: left hand drives the statue, right hand drives the daffodil — both responsive in the same frame.

Left hand: statue VAT · Right hand: daffodil interaction.

3DGS in Unreal — Volinga + SplatRenderer

Integrated 3DGS assets into Unreal using both the Volinga plugin and SplatRenderer, then layered additional FX on top of the splats in Unreal so the splat content sits inside the scene rather than reading as a flat insert. Cross-checked rendering between the two plugins to compare visual quality and integration overhead.

3DGS in Unreal with additional FX passes — splat sitting inside the scene, not on top of it.

LED Wall Deployment

Final composition pushed to LED Wall via disguise. Pre-rendered MP4 deliverables were transcoded to MOV HAPQ for clean disguise ingest, then a load test validated playback stability before shoot day. The disguise + RenderStream path also drove a live Unreal feed for the interactive moments.

Pilot footage from the LED Wall shoot day, featuring the Niagara interaction system.