Ray-marching in Thurston geometries

This project started from the ray marching hyperbolic virtual reality simulation (for mobile devices) by Henry Segerman and Michael Woodard, which is in turn based on the full simulation.

This version is as independent of the underlying geometry as possible. It comes with an API to

• build and animate scenes in a given geometry
• define objects, lights, materials, etc
• implement new geometries (or new models of existing geometries)

This project started at the Illustrating Mathematics semester program at ICERM.

Visit the website https://3-dimensional.space for demos, math explanations, and documentation.

Examples

The project contains numerous ready to use examples. It contains scenes in the various geometries and demonstrates the features of the API. To run the examples on your own computer, you need a local server.

Running a local server

• Download the project (for a basic usage the dist directory is enough)
• Start a local server making sure that the root of the server correspond to the dist. This can be easily done with Python 3 using the command

  python -m http.server

• With a browser, visit the page http://http://localhost:8000/examples/index.html (adapt the URL depending on your local server)
• Enjoy!

Exploring the examples

The examples tagged with (VR) are made for virtual reality. They should work with any VR headset supported by the three.js library. When loaded, those examples have a button Enter VR at the bottom on the screen. Clicking this button should launch the simulation in the VR headset (you may first need to allow your browser to interact with the VR system).

Items flagged with (PT) incorporate a path tracer. Hit p to launch the path tracer.

The default controls are the following.

Command	QWERTY keyboard	AZERTY keyboard
Yaw left	a	q
Yaw right	d	d
Pitch up	w	z
Pitch down	s	s
Roll left	q	a
Roll right	e	e
Move forward	arrow up	arrow up
Move backward	arrow down	arrow down
Move to the left	arrow left	arrow left
Move the the right	arrow right	arrow right
Move upwards	'	ù
Move downwards	/	=

Building your own scene

To build your own scene, visit the tutorials from the documentation. You can also browse the examples.

Development

If you extend the project, you need to install the library with npm. You must first install this tools following the instructions for your operating system. (On Mac one can use homebrew to install npm.)

Installation

• clone the git repository of non-euclidean-vr
• install the dependencies with the command

  npm install

Build

The packages are built with webpack. The builder is configured to produce one file for each geometry (with a name of the form thrustonXXX.js). The module exposed for each geometry are defined in the files /src/thursontXXX.js. The command to build the packages is

npm run build

Development environment

In a development phase, one can use webpack dev server. Run the command

npm run dev

The webpack dev server will serve the content of the dev directory at the address http://localhost:9000/ Any change in the code will be updated automatically (without having to rebuild the code).

To update the documentation (compiled from docstrings), run the command

npm run doc

License

Released under the terms of the GNU General Public License, version 3 or later.

Main contributors

(alphabetical order)

• Rémi Coulon @remi-coulon

  Rémi Coulon is partially supported by the Centre Henri Lebesgue ANR-11-LABX-0020-01 and the Agence Nationale de la Recherche under Grant Dagger ANR-16-CE40- 0006-01.

• Sabetta Matsumoto @sabetta

  Sabetta Matsumoto is partially supported by NSF grant DMR-1847172 and the Research Corporation for Scientific Advancement.

• Henry Segerman @henryseg

  Henry Segerman is partially supported by NSF grant DMS-1708239.

• Steve Trettel @stevejtrettel

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.