Splash, a multi-projector video-mapping software
For a more complete documentation, go visit the wiki.
Table of Contents
Splash is a free (as in GPL) modular mapping software. Provided that the user creates a 3D model with UV mapping of the projection surface, Splash will take care of calibrating the videoprojectors (intrinsic and extrinsic parameters, blending and color), and feed them with the input video sources. Splash can handle multiple inputs, mapped on multiple 3D models, and has been tested with up to eight outputs on two graphic cards. It currently runs on a single computer but support for multiple computers mapping together is planned.
Although Splash was primarily targeted toward fulldome mapping and has been extensively tested in this context, it can be used for virtually any surface provided that a 3D model of the geometry is available. Multiple fulldomes have been mapped, either by the authors of this software (two small dome (3m wide) with 4 projectors, a big one (20m wide) with 8 projectors) or by other teams. It has also been tested sucessfully as a more regular video-mapping software to project on buildings, or onto moving objects.
Regarding performances, our tests show that Splash can handle flawlessly a 3072x3072@60Hz live video input, or a 4096x4096@60Hz video while outputting to eight outputs (through two graphic cards) with a high end cpu and the HapQ video codec (on a SSD as this codec needs a very high bandwidth). Due to its architecture, higher resolutions are more likely to run smoothly when a single graphic card is used, although nothing higher than 4096x4096@60Hz has been tested yet (well, we tested 6144x6144@60Hz but the drive throughput was not sufficient to sustain the video bitrate).
Splash can read videos from various sources amoung which video files (most common format and Hap variations), video input (such as video cameras and capture cards), and Shmdata (a shared memory library used to make softwares from the SAT Metalab communicate between each others). An addon for Blender is included which allows for exporting draft configurations and update in real-time the meshes. It also handles automatically a few things:
- semi automatic geometric calibration of the video-projectors,
- automatic calibration of the blending between them,
- experimental automatic colorimetric calibration (with a gPhoto compatible camera)
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.
This project is made possible thanks to the Society for Arts and Technologies (also known as SAT). Thanks to the Ministère du Développement économique, de l'Innovation et de l'Exportation du Québec (MDEIE).
Splash relies on a few libraries to get the job done. These libraries are:
- OpenGL, which should be installed by the graphic driver,
- libshmdata to read video flows from a shared memory,
- GSL (GNU Scientific Library) to compute calibration,
- portaudio to read and output audio,
- Python for scripting capabilities,
- GPhoto to use a camera for color calibration.
A few more libraries are used as submodules in the git repository:
- FFmpeg to read video files,
- GLFW to handle the GL context creation,
- GLM to ease matrix manipulation,
- ImGui to draw the GUI,
- doctest to do some unit testing,
- Piccante to create HDR images,
- Snappy to handle Hap codec decompression,
- libltc to read timecodes from an audio input,
- JsonCpp to load and save the configuration,
- stb_image to read images.
- ZMQ to communicate between the various process involved in a Splash session,
- cppzmq for its C++ bindings of ZMQ
Also, the Roboto font is used and distributed under the Apache license.
Compilation and installation
The current release of Splash has currently only been compiled and tested on Ubuntu (version 16.04) and Mint 18 and higher. The easy way to install it is to get the Debian archive from the release page, and install it with :
sudo apt install <download path>/splash-<version>-Linux.deb
You can also compile Splash by hand, especially if you are curious about its internals or want to tinker with the code (or even, who knows, contribute!). Note that although what follows compiles the develop branch, it is more likely to contain bugs alongside new features / optimizations so if you experience crash you can try with the master branch.
The packages necessary to compile Splash are the following:
- Ubuntu and derivatives:
sudo apt install build-essential git-core cmake libxrandr-dev libxi-dev sudo apt install mesa-common-dev libglm-dev libgsl0-dev libatlas3-base libgphoto2-dev libz-dev sudo apt install libxinerama-dev libxcursor-dev python3-dev yasm portaudio19-dev sudo apt install python3-numpy
- Archlinux (not well maintained, please signal any issue):
pacman -Sy git cmake make gcc yasm pkgconfig libxi libxinerama libxrandr libxcursor pacman -Sy mesa glm gsl libgphoto2 python3 portaudio zip zlib
Once everything is installed, you can go on with building Splash:
git clone git://github.com/paperManu/splash cd splash git submodule update --init ./make_deps.sh mkdir -p build && cd build cmake .. make && sudo make install
You can now try launching Splash:
If you want to have access to realtime scheduling within Splash, you need to create a group "realtime", add yourself to it and set some limits:
sudo addgroup realtime sudo adduser $USER realtime sudo cp ./data/config/realtime.conf /etc/security/limits.d/
And if you want the logs to be written to /var/log/splash.log:
sudo adduser $USER syslog
Then log out and log back in.
If you want to specify some defaults values for the objects, you can set the environment variable SPLASH_DEFAULTS with the path to a file defining default values for given types. An example of such a file can be found in data/splashrc
And that's it, you can move on the the Walkthrough page.
To learn how to configure and use Splash, the best resource currently is the Wiki page on Github.