ATLAS · CERN · 3D Visualisation

CGV-WEB

Calorimeter Geometry Viewer Web

CGV-WEB renders CERN ATLAS calorimeter collision events in real-time 3D, colour-coding each detector cell by energy deposit. Built on Rust/WebAssembly, Three.js, and backed by ROOT data pipelines, it is NIPSCERN's most technically ambitious project — led by Chrysthofer Arthur — and is being integrated into the ATLAS Control Room at CERN.

Open Full CGV View on GitHub All Projects
Rust / WebAssembly Three.js JavaScript ROOT ATLAS TileCal · LAr · HEC Open Source Active
ATLAS Control Room Integration — CERN
CGV-WEB is being integrated into the ATLAS Control Room at CERN, where it will appear on the main display screen used by researchers monitoring live particle collisions in the LHC. This milestone represents NIPSCERN's most direct contribution to the operational infrastructure of a major LHC detector, placing work produced at UFJF on the walls of one of the world's most advanced physics facilities.
Live Preview

ATLAS Calorimeter — Interactive Preview

Interactive 3D rendering of the ATLAS calorimeter. Each coloured cell represents energy deposited by particles in a simulated collision.

Technical Stack

CGV-WEB is designed for zero-installation deployment: it runs entirely in the browser, yet achieves native-level performance through a Rust/WebAssembly core and hardware-accelerated Three.js rendering. The data pipeline reads ROOT files produced by ATLAS reconstruction software and converts them to a binary format optimised for the WASM engine.

Rust / WebAssembly
Core geometry & event engine
Detector geometry construction, event data parsing, and energy-to-colour mapping are handled in a Rust crate compiled to WASM. Achieves near-native performance with a compact binary and no garbage-collection pauses.
Three.js r160
WebGL 3D rendering
OrbitControls for interactive camera, custom MeshPhongMaterial shaders for energy colour gradients (blue → yellow → red), and per-frame frustum culling. Cell meshes are created or destroyed as events change.
ROOT
ATLAS data pipeline
Upstream data originates from ROOT files (.root) produced by ATLAS Athena reconstruction. A Python/C++ converter extracts calorimeter cell energies and writes a compact binary format consumed by the WASM engine.
JavaScript Frontend
UI, i18n, event bus
ES-module orchestration layer: initialises WASM, wires Three.js scene, handles UI events (wireframe toggle, beam axis, layer visibility), renders HUD cell tooltip on hover, and applies NIPSCERN design system styling.

Sub-Detectors Visualised

TileCal Barrel
3 radial layers · ±z · 10 η × 64 φ bins per layer
LAr EM Barrel
4 depth layers · ±z · 28–56 η × 64 φ bins per layer
HEC Endcaps
4 disk layers · ±z · 8 η × 32 φ bins per endcap
Lead Developer
CGV-WEB · NIPSCERN

Chrysthofer Arthur leads the development of CGV-WEB, co-advised by Prof. Luciano Manhães de Andrade Filho. He is responsible for the Rust/WASM engine architecture, the ROOT data pipeline integration, and the ATLAS Control Room deployment coordination.

Origin — CaloGeoView: CGV-WEB is the online evolution of CaloGeoView, a desktop visualisation tool originally developed by Dr. Luciano Manhães de Andrade Filho during his PhD at UFJF. The Rust/WASM rewrite makes it accessible in any modern browser — no installation required.

Development Roadmap

CGV-WEB is in active development. The priorities below are driven by the ATLAS Control Room deployment timeline.

Done
Three.js geometry rendering
TileCal barrel, LAr barrel, HEC endcaps fully rendered with energy colour-mapping.
Done
Interactive controls & HUD
Orbit camera, wireframe toggle, beam axis overlay, layer visibility, cell-hover tooltip with energy readout.
In Progress
Rust/WASM engine
Porting geometry construction and event parser to a compiled Rust crate for maximum performance in the browser.
In Progress
ROOT data pipeline
Python/C++ extractor converting ATLAS .root files to a compact binary format streamed to the WASM engine.
Planned
ATLAS Control Room deployment
Final integration on the primary display in the ATLAS Control Room at CERN. Researchers will use CGV-WEB to inspect live collision events.
Planned
Forward calorimeter (FCal) support
Extending geometry to include the FCal copper and tungsten electromagnetic and hadronic sections.

Try CGV-WEB

Load the full application — import a ROOT event file, interact with the 3D calorimeter geometry, and explore energy deposits cell by cell.

Open Full CGV App View on GitHub