LJ is like a video projector where you fire images and forget. Lasers are dangerous : you can really fire real world objects. That's why you really shouldn't forget your lasers and go drink a beer.
As content creator, it's damn easy to send frames : LJ do the heavy lifting for up to 4 lasers live actions. Think creative like games, Laser "battles", planetarium, sharing available lasers in demoparties for competition,...
- Frame *generators* to one or more lasers. Generators can be program "plugins" managed by LJ or you can feed the "connectors" directly. Remember with laser : *one frame = one polyline*, like in LOGO.
- A "tracer" per etherdream/laser that take its given point list, correct geometry, recompute in laser controller coordinates, send it to its controller and report its status to the "manager".
- A "manager" that talk to all tracers (which point lists to draw, new geometry correction,...), handle IOs (webui functions, OSC commands,...) and plugins.
- A web GUI in html, css, and vanilla js. *Yes, there is a builtin simulator* so you can create without actual lasers. This UI can be used in a tablet, computer, whatever. You can open www directory and load html files. To not mess with user computer, it's "bring your own webserver".
- Frame *connectors* for pointlists, if you don't want to talk directly to the network available database (redis). Each "tracer" is instructed to get one of the avalaible pointlist in redis.
LJ accept up to 4 groups = virtual "scenes" of 4 "pointlists" each (= one pointlist per laser), so up to 16 pointlists can be sent to redis at anytime from anywhere in the network. The idea behind this is to easily share actual lasers. Imagine in demo party :
Erica needs 4 lasers, that's the 4 pointlists of "scene" 0.
Paula and Jennifer use only 2 lasers each, so they can share "scene" 1.
And so on..
To change current scene used by lasers/tracers use the command : /scene/scenenumber/start 1
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# How talk to frames connectors
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One "frame" must be formated like /pl/scenenumber/lasernumber pointlist.
See command reference for extensive documentation, but /pl is the only one you need to draw something. The webUI is here to masquerade all these commands.
RJ 45 IP network : gigabits only !! wifi and wired 100 mpbs doesn't work well with several lasers. Seriously : if you experience frame dropsyou need to upgrade your network and use a dedicated computer to run seperately main program from plugins, youtube,...
Important : for best performance LJ is meant to run in a dedicated computer especially with multiple lasers and highly multitasked load : if you watch video, use live webcam face recognition, webui simulator,... and run LJ on the same computer, well you need a bunch of cores. If you don't, spread the load : you can use webui on a tablet, the livecam on a phone, run pointlists generators on another computer,...
The server/network/webUI idea allows to spread cpu intensive tasks on different cpu cores and especially give tracers enough cpu to feed etherdreams DACs smoothly. Of course all this can happen in one computer if *you have enough cpu/computers/network ressources*.
It's obviously overkill for one laser in a garage, but for several laserS games events, laserS art, laserS competition, laserS planetarium,... LJ will handle the complexity. Content providers like artists, demomakers,... just need create plugin in whatever langage, send the points to redis.
LJ is tested with Firefox, supports Linux and OS X. Windows is unkown but welcome, if someone want to jump in.
- Web User Interface in your browser : open www/index.html. Javascript is needed. By default it connect to localhost. If you want to control remotely, you need to change the uri line in LJ.js.
- A compiled version for os x and linux of nannou.org etherdream+laser emulator is included. For more informations, like license see https://github.com/nannou-org/ether-dream
The configure script to enter your etherdreams IPs,... is launched during install. You can use anytime, i.e if your network/etherdream setup change : python3 configure.py
- Webserver ?
A webserver is useful if you want to use the webUI remotely. Bring Your Own Webserver.
1/ Say the laser server computer (running LJ) IP is 192.138.1.13, the client computer is 192.168.1.52, First remember to check on the server computer, if the redis server is listening to the right IP : edit /etc/redis/redis.conf
The server approach is based on redis, so you can write and run your laser client software in any redis capable programming langage (50+ : https://redis.io/clients). An external program that just send pointlists to redis is a "client". If you want some interactions from the webUI, like text status area support, crash detection, autostart,... it's a "plugin" and some default code is needed. LJ and plugins signaling is over OSC.
- Generate at least one pointlist array (say a square) with *enough points*, one point is likely to fail for buffering reason.
- Feed your point list array in string format to redis server. i.e use "/pl/0/1" redis key to feed scene 0, laser 1. See /pl/ command in command reference below how to send your pointlist to i.e /pl/0/1 redis key.
First open custom1.py and learn how to declare different objects. custom1.py is a 2D shape example in 3D rotation (red/green anaglyph rendering) that use 2 layers : one for left eye and one for right eye. custom1 is a copy of square.py
Dest1 = lj.DestObject('1', 1, True, 1 , 0, 1) # Dest1 will send layer 1 points to scene 0, laser 1
3/ Different layers to one laser ?
You should consider adding all your points to one layer, but same as 1/ it's a destination problem, just add another destination with the same scene/laser for this layer
Dest1 = lj.DestObject('1', 1, True, 1 , 0, 0) # Dest1 will also send layer 1 points to scene 0, laser 0
4/ I want to animate/modify anything on the fly : I'm doing a game and suddenly my hero change color.
It's a drawn object problem : there is two kind of drawn ojects :
- "Fixed" objects : you generate points in 2D from 0,0 top left and 500,500 is bottom right. Say Hero is a Fixed Object, you can directly change value of
- "Relative" Object : is a kind of laser sprite : your points in 'objectname.xy' has to be around 0,0,0. The other properties let you describe the actual position (xpos, ypos), resize,..
i.e for a character "PNC" vanishing in one point declared as a "Relative" Object, you can decrease resize parameter : PNC.resize
DrawDests() will take care of all your declared drawn elements/"objects" and Destinations to generate a point list per scene/laser sent to redis. In client point of view a "pointlist" is the sum of all its declared "layers".
2 compiled nannou visualisers are included, one for Linux, one for macOS. It's pretty old version but much more compatible with "old" processors/computer.
To use this visualiser as one of LJ's lasers, use configure.py to set one laser to the IP of the computer running the visualiser. Relaunch LJ. One visualiser per computer.
- Because wifi will always finally sucks for many reasons, our computers (LJ server and plugins) are *gigabits wired* with IP 192.168.1.10 and after. Don't trust end user gear marketing on wifi. We have a big gigabits switch for the *laser only lan*. We provide Internet through wifi on a different network like 192.168.2.x if really needed.
The need for a dedicated computer to act as "laser server" usually depends on how many lasers you want to control and your main computer load. If you seen flickering with small point lists, try the dedicated computer idea and/or stop process interfering like redis monitoring,...
For nice lines and angles all user pointlists are automatically resampled by tracers. There is 2 cases defined for resampling strategy : short and long distance between 2 points.
short distance : has one step : (1.0, number repetition at destination position). 1.0 = 100% = end point of the line between the 2 points. For example : (1.0, 8) means the end point will be repeated 8 times.
long distance has 3 steps : (0.25, 3), (0.75, 3), (1.0, 10) : means an extra point at 25% is created and repeated 3 times, another at 75% repeated also 3 times and destination point is repeated 10 times.
For glitching experience you can change resampling strategy live with "resampler" command. See command reference. [short distance, long distance] = [(1.0, 8),(0.25, 3), (0.75, 3), (1.0, 10)]
LJ is compatible with TLL and analog modulation. Each point color is an int value, wich is simply the hex color in decimal. Example : white = #fffff = 16777215
This program suppose that the ether dream is configured in a certain way especially for its IP address. We write an autoplay.txt file inside an SD Card within the ether dream DAC, with the following lines you can adjust i.e for pps or fps. Yes, there is a builtin DHCP client in the ether dream DAC but if you run multiple lasers, having a fixed dedicated network makes you focus on laser stuff.
See links section for great etherdream managing tools.
About hardware setup, especially if you have several lasers : ILDA cables are insanely expensive. For each DAC, buy a very small ILDA cable and RJ 45 cable, all DAC goes to a local switch and only one long cable to your
You may also consider the Power Over Ethernet 'POE' option. Buy a POE splitter and connect everything to the ether dream fixed near your laser. You can have then a simple and very long network cable and use a Power Over Ethernet injector or switch close to the driving computer. Beware some vendors use 24V POE Injector : POE injectors and splitters must match.
2 useful and always working tools from j4cdac github repository : sitter and talk
- Sitter will display all real etherdreams available on the network and their state (playing, idle,...). python sitter.py or use the compiled version (for macOS).
- Talk : will draw a 4 colors square. python3 talk3.py
- Use talk3 in ethertools directory : this ensure your computer can connect to the etherdream. See ethertools chapter in this readme. If talk3 doesn't works, check the hardware, connections,...
python3 talk3.py -i etherdreamIP
- You should see "connected to yourLJserverIP" on webUI. If not : LJ is not started / reload webpage / your network configuration is bad / a wrong IP in the configure parameters : python3 configure.py.
- Switch to simu page. If you don't see anything : check redis server or your points in redis doesn't respect pointlist formatting (see command reference).
- If talk3 works but you don't see your points : click on the Grid icon in Align page. This will override your pointlist and display squares. If Grid works : recomputed points by tracers are "bad" with given values in LJ.conf.
- too small movement : some lasers (with small angle like 40°) won't display anything if zoomx/zoomy are too small. Increase zoomx / zoomy in LJ.conf. Try 50-100 values.
- off center : check in LJ.conf centerX and centerY. Reset them to 0.
- not enough points.
*Don't kill your scanners : becareful with kpps setting.*
