SimView Visualizer

SimView is a powerful and interactive tool for visualizing 3D models and terrain data in simulations. It enables you to explore and analyze multiple simulation scenarios (batches) within a shared environment, all defined through an intuitive JSON format or a Python API.

Whether you're simulating physical objects or comparing different runs, SimView provides a flexible and efficient way to bring your data to life using a web-based interface powered by Three.js.

Documentation

Full documentation — usage guides, CLI reference, the JSON format specification, the API reference, and developer/architecture docs — is available at:

https://vlk-jan.github.io/simview/

Want to try it without installing anything? There's a live browser demo (always up-to-date with the current code, no backend needed).

Features

• Batched Simulations: Visualize multiple simulation instances side-by-side.
• Shared Terrain: Efficient rendering with shared terrain across all batches.
• Interactive UI: Web-based controls for playback, camera, and data inspection.
• Python API: Easy-to-use API for generating scenes and launching the visualizer directly from your code.
• JSON Support: Load and save simulation data using a portable JSON format.
• Remote Files: Open a scene straight off a compute host with simview host:path/to/scene.json — fetched over SSH, compressed on the wire, and cached locally.
• Comparing Runs: Merge several scene files into one, taking whole files or just picked batches — simview gt.json method_a.json#1 method_b.json#1.

Quick Start

The easiest way to get started is to run the provided example script:

python example.py

This script demonstrates how to use the Python API to create a simulation with wavy terrain, dynamic bodies, and time-series data.

The Python authoring API (simview.scene, simview.state, simview.model) depends on torch and einops. Install them with the optional authoring extra shown below. Only these are needed to build simulations; viewing an existing JSON file does not require torch.

Installation

Requires Python 3.12+.

From PyPI

To only view existing simulation JSON files:

pip install simview

To also author simulations from Python (installs torch and einops):

pip install "simview[authoring]"

From source

For working on SimView itself (or to track an unreleased commit), install an editable checkout instead:

pip install -e .              # viewing only
pip install -e ".[authoring]" # viewing + authoring

For independent use of this repository, use venv or uv:

python -m venv .venv
source .venv/bin/activate
pip install -e ".[authoring]"

uv sync --extra authoring
source .venv/bin/activate

License

SimView is distributed under the BSD 3-Clause License. The web interface vendors uPlot, three.js, and chroma-js (all MIT licensed) under simview/static/lib/ so the viewer works fully offline — see the documentation for details. All third-party libraries used by SimView are permissively licensed (MIT/BSD), so there are no licensing restrictions on commercial use.