n i n

User manual • Developer manual • Testimonials / Reviews • List of known nin projects

^{DISCLAIMER: This is a tool created for internal use by Ninjadev, and is open sourced to share ideas with and get feedback from the community. You are free to use it, according to the License, but we will not necessarily provide support and may at any time add, change or remove features as we require for our productions.}

nin is ninjatool

nin is Ninjadev's internal demo tool. It is a tool for easing development of browser-based WebGL demos. Core features include:

• Node-based demotool, effortlessly reuse your effects, scenes, and create crazy transitions.
• Livereloading of shaders and scenes in the browser. No more manual recompilation!
• Tight THREE.js integration for all your WebGL needs.
• Compile and pack your WebGL demo to a .png.html file for easy compo delivery

The backend component is written in node.js, and keeps track of and recompiles changed files. The frontend is created using React, and communicates with the backend over websockets.

User manual

Installing nin

To install nin simply run the command:

npm install -g ninjadev-nin

This projects requires node version 7.9.0 or newer. You can install node from packaging here or download zipped source from this page and verify signatures with the guide here;

You will also need git installed for project generation to work. New project created with nin get a default .eslintrc suitable for WebGL demos with THREE.js.

Getting started

Running nin new <dirname> will create the specified directory and initialize a new nin project inside. Running nin run inside the newly created project will make it accessible on http://localhost:8000.

nin creates a manifest file called nin.json. You should fill out this file with the title of your demo, the authors, a description, song metadata, and even a google analytics tracking code to collect statistics. The metadata is then used to generate html meta-tags in the head of the demo, as well as in the metadata segment of the .png.html file. The png metadata can be viewed with a command such as pngcheck -c -t -7 bin/demo.png.html on linux.

My First Node

Create a new node by clicking Generate -> THREE NODE in the frontend menu. The node will be placed in src/nodeName.js and added to the graph in res/graph.json. You must connect the node yourself to the output node. This is done by setting connected.screen to nodeName.render as in the example below, where nodeName is the id of the node you want to connect to the display.

{
    "id": "root",
        "type": "NIN.RootNode",
        "connected": {
            "screen": "nodeName.render"
        }
    }
}

Shader Nodes

Create a shader node by clicking Generate -> Shader Node in the frontend menu. It generates the file src/nameOfTheShaderNode.js and the folder src/shaders/nameOfTheShaderNode/. To get livereload on shader change, you shader must be specified in the options object of your node in res/graph.json, the shader generator will do this for you. If needed, you can access the shader through the global SHADERS object, by writing SHADERS.nameOfTheShader.

Compiling

The nin compile command will create a single file bin/demo.png.html that contains all the code and resources of your demo. Base64 and PNG compression magic is used to achieve this. It will at the same time output a file without PNG compression, bin/demo.html, which will be slightly larger, but compatible with a wider range of devices (especially smartphones). For faster compiles, pass the flag --no-closure-compiler. This will only concatenate js files, without any minifying.

.ninrc

Some of nin's settings can be overriden by placing a .ninrc file in your home directory. Currently, keyboard shortcuts is the only behavior which can be changed in the .ninrc. The list of canonical names for keybindings can be found in nin/frontend/app/scripts/directives/menubar.js.

An example .ninrc looks like the following:

[keybinds]
startRendering=left
stopRendering=right

Rendering to video

1. nin run.
2. Open nin in your browser, navigate to the frame you want to render from, and press R. This will start dumping single frames as numbered .PNGs in bin/render/ in your project folder.
3. Refresh etc every time WebGL crashes.
4. When you have rendered all the frames: nin render. You need ffmpeg (ffmpeg.org) installed for this.
5. The demo is now available at bin/render/render.mp4.

Each frame will take up to around 4MB on disk, and the finished .mp4 will be on the order of 1GB when rendered, so make sure you have enough disk space. Expect to render maybe a frame or two per second.

Developer manual

Setup

You will need to have node installed.

Running make in the nin folder will build and compile the entire project. Running npm link will add nin to your node binaries path, making it available globally.

Developing

First, run nin run inside your project. If you wish to develop on the frontend, running make run inside nin/frontend/ makes webpack rebuild the frontend on file change. You only need to rerun nin run if you change files in either nin/dasBoot or nin/backend.

Working with scenes

Usually, your demo will be a series of connected scenes. This section covers how to work with them.

Adding scenes

Adding a scene is quite straight forward, once you become good friends with graph.json!

How to add the first scene to a demo

This is what you need to to do get your first scene wired up and ready to go!

How to add a scene at the end of the demo

Here is an example of how to prolong the demo by adding a new scene at the end.

How to add a new scene between two existing scenes

Sometimes you want to squeeze in a new scene between two other scenes that you already have in your demo. Often you will perhaps only shorten the preceding scene and leave the start of the following scene intact. But for completeness, here is an example where we both shorten the previous scene, and chop down the beginning of the following scene.

Adding backgrounds to scenes

Adding backgrounds ain't all that hard, once you have an overview of whats needed!

First of all, make sure there is an actual existing file containing the code for your background. If you want to render your background on a canvas the content should be something like the example below. Note that to actuall work with the content, you will probably want to be able to see it first. To make the content visible, you should go through the steps with adding it the scene and in graph.json, as described below the example.

(function(global) {
  const F = (frame, from, delta) => (
    frame - FRAME_FOR_BEAN(from)) / (FRAME_FOR_BEAN(from + delta) - FRAME_FOR_BEAN(from)
  );

  constructor(id) {
    super(id, {
      outputs: {
        render: new NIN.TextureOutput()
      }
    });

    this.canvas = document.createElement('canvas');
    this.ctx = this.canvas.getContext('2d');

    this.width = 1024;
    this.height = 1024;

    this.canvas.width = this.width;
    this.canvas.height = this.height;

    this.output = new THREE.VideoTexture(this.canvas);
    this.output.minFilter = THREE.LinearFilter;
    this.output.magFilter = THREE.LinearFilter;

    // ... other constructor content, such as initializing your Random.
  }

  update(frame) {
    super.update(frame);
    // Other stuff you want to do each frame
  }

  // The warmup block exsist to prevent stutter related to compiling shaders when the scene starts.
  // Usually shaders are compield for your GPU just in time at the moment they are first called.
  // This can take some time, and result in perceived jitter at the start of your scene.
  // To prevent this, when NIN starts running a demo, before the playback looks like it begins, it will run through each scene and call its `warmup`.
  // In practice, this is like rendering one frame from each scene, so that all shaders are loaded before the smooth playback you want to show off.
  warmup(renderer) {
    this.update(6710); // the first frame in this scene cointaining the shaders you want pre-loaded.
    this.render(renderer);
  }

  render() {
    this.output.needsUpdate = true;
    this.outputs.render.setValue(this.output);
  }

  global.greetsBackgroundCanvas = greetsBackgroundCanvas;
})(this);

Once you've decided on a name for the background-class, you should add it to the graph.json (.../demo_repository/res/graph.json). It has to be added both as a separate node, and as an input to the scene you wish to use it in. Example:

[
  // loads of graph.json content
  // ...
  // },
  {
    "id": "the_scene",
    "type": "the_scene",
    "connected": {
      "param_name": "background_class_name.render"
    }
  },
  // more graph.js
  // ...
  // },
  {
    "id": "background_class_name",
    "type": "background_class_name"
  }
  // possibly more graph.json, but you've just added this, right? =P
]

Note the .render after the backgrounds class name in the connected section!

Finally, you need to add the new background to your scene. This recquires a couple of things.

First, you need to take make sure the background class is declared as an input in your constructors call to super. Then, in your constructor, you need to define the mesh your background class will draw on, its size and location, and add it to your scene.

At this point you should be mindfull of whether you make your background render from both sides, or only the front or back side. If you make a background in the form of a "sky box" that engulfs the scene in front of the camera, you'll likely want to set the drawing side to side: THREE.BackSide. (This is handy if you have a lot of camera movement and can't guarantee that that anything in your scene wil neccessarily be infront of any given plane that you might have wanted to use as a background.) Doing so should prevent your background from rendering in front of the scene you are trying to display and blocking the view of it.

After that, in your scenes update-function, you need to ensure that your background also gets updated. That is done by setting assigning materials' (mesh you declared in the constructors') map to the background-input. Note that you at this point probably should also set the flag for that it needs updating.

Lastly, you should be aware that in regards to the camera and general movement in the scene, the backgound can be considered just like any other object. This implies that for a scene with a lot of camera movement, you can both make the background an object that moves together with the camera and appears static, or you can make it rotate wildly.

Example:

(function(global) {
  class the_scene extends NIN.THREENode {
    constructor(id, options) {
      super(id, {
        camera: options.camera,
        outputs: {
          render: new NIN.TextureOutput()
        },
        inputs: {
          background: new NIN.TextureInput()
        }
        // Other inputs to super
      });
    }
    // more constructor input
    this.background = new THREE.Mesh(
      new THREE.BoxGeometry(skybox_x_size_in_scene, skybox_y_size_in_scene, skybox_z_size_in_scene), // Note that these are independent of the dimentions you declare for the canvas in the background. E.g. you can work on a 1024 x 1024 x 1 canvas in your background that is spread out on a 3440 x 1440 x 2048 surface in the scene. You'd probably want to make the aspect ratios equivalent or draw one flat surface on each side of a 3d box in your scene though)
      new THREE.MeshBasicMaterial({color: 0xffffff, side: THREE.BackSide})
    );
    this.scene.add(this.background);
    // other constructor code
  }

  update(frame) {
      super.update(frame);
      this.background.material.map = this.inputs.background.getValue();
      this.background.material.needsUpdate = true;
      // ...
      // The actual focus of your scene!
      // ...
      // If this is the camera movement in your scene
      var camera_angle = frame * related + math / expression;
      var this.camera.position.x = initial_position_x + Math.sin(camera_angle) * speed_multiplier;
      var this.camera.position.y = initial_position_y + Math.cos(camera_angle) * speed_multiplier;
      var this.camera.position.z = initial_position_z;
      this.camera.lookAt(new THREE.Vector3(initial_position_x, initial_position_y, poi_z));
      // Note that the initial_position_... above ^ can be linear expressions related to the frame
      // Then you can do like this to to keep the background still relative to the camera:
      this.background.rotation.z = -cameraAngle;

      // Or move it relative to the camere at a pace independently of the cameras movement relative to the point it is directed at:
      this.background.rotation.z = -cameraAngle + Math.sin(frame_related * constants + and_or_bean_related_movement_params / Math.PI * related_becuase_radians) * factor_controllong_intensity + other_linear_offsets;

      // You can also apply transforms to the background relative to the camera here:
      this.background.scale.x = -1; // Inverts / mirrors the background along the x-axis
  }
})(this);

Randomness

To ensure that random things happen consistently across runs it is recommended to use the Random-class rather than Math.random(). Set up Random by initializing it in your constructor like so:

constructor(id, options) {
  ...
  this.random = new Random('seedString');
  ...
}

Then use the random generator you just created like this:

var randomNumber = this.random();

Time and timed events

A lot of making a demo is syncing what's happening on the screen with the music.

A BEAN can be described as the smallest possible resoluton of the beat.

Working with BEANs directly will usually not give you a smooth 60 FPS animation. BEANs are incremented less often than 60 FPS. A common approach is using frame with FRAME_FOR_BEAN instead. E.g. Instead of doing

var startBean = 1;
var endBean = 20;
var fractionIn = (BEAN - startBean) / (endBean - startBean);

do

var startFrame = FRAME_FOR_BEAN(1);
var endFrame = FRAME_FOR_BEAN(20);
var fractionIn = (frame - startFrame) / (endFrame - startFrame);

Notes on the update(frame)-function

In your scene-function, you can define an update function.

update(frame) {
  // The coolest of code
}

This will run for every frame.

Movement

You might have defined an object in your scene, such as a box, the camera, or a light source, which you want to move within your scene. To aid you in doing this smoothly, there are some predefined functions you can utilize.

The most important ones are:

• smoothstep
• lerp

They all have the same API: lerp(startValue, endValue, t)

When t is smaller than or equal to 0, startValue is returned. When t is between 0 and 1, a value between startValue and endValue is returned, depending on which interpolation function you're using. When t is larger than 1, endValue is returned.

smoothstep

For more details, check out http://en.wikipedia.org/wiki/Smoothstep .

lerp

Music

How to add music to your demo

In the nin.json-file you can define the music-section directly in the root. Here you can specify

• path: relative path to the music file
• bpm: the tempo of your music in beats per minute

Sample music configuration:

"music": {
  "path": "res/music.mp3",
  "bpm": 190,
  "subdivision": 12,
  "BEANOffset": 0
},

For details on how this section is processed further you can check out nin/dasBoot/BEATBEAN.js.

Text

How to write text, or letters in general, to your 2D canvas.

Out of the box you can write text to your canvas like this:

this.canvas.getContext('2d').fillStyle = '#ffffff'; // The color of the text you are going to be displaying
this.canvas.getContext('2d').font = 'bold ' + (24) + 'pt Arial'; // Pattern: weight [size]size_unit font_name
this.canvas.getContext('2d').textAlign = 'center'; // possible values: left, right, center, start (locale dependent), end (locale dependent)
this.canvas.getContext('2d').textBaseline = 'middle'; // possible values: middle, top, bottom, alphabetic, hanging, ideographic
this.canvas.getContext('2d').fillText('Hello Nin!', x_position_on_canvas, y_position_on_canvas);

Beware that this will not replace any text previously drawn. To obtain a blank slate you have to either clear or draw over previously shown text.

Reference for styling of text drawn with fillText: https://developer.mozilla.org/en-US/docs/Web/API/Canvas_API/Tutorial/Drawing_text#Styling_text .

Linting

The frontend part of this project uses ESLint for linting. See the .eslintrc.js file in the frontend part of this project.

The demo itself and our own dasBoot uses the Google Closure Linter, please see this link for installation information. https://developers.google.com/closure/utilities/docs/linter_howto Use the --nojsdoc flag.

Publishing nin

To publish nin, checkout a new branch, run make bump-version, git push, get it merged, and Travis will automatically publish a new release after master has finished building.

Notes on working in windows

The prerequisites remain the same, you at least need Node.

To build and compile the entire project, for now, you need only run npm start in the root of the nin-repo. To run nin without linking up through npm you can replace the nin-command with node path-to-ninrepo/nin/backend/nin. E.g. when you are in a project folder of a demo, and you want to run it with your freshly compiled nin directly, you can run node path-to-ninrepo/nin/backend/nin run instead of nin run.

If you want to run it from powershell regularly, you might want to make an alias in your profile akin to this:

function nin
{
    param($argz)
    node $ninRepoPath\nin\backend\nin $argz
}

Alternatively you can use the psNin.ps1 script from your demo, or call it from anywhere if you supply it to the optional $demoPath parameter.

Testimonials / Reviews

nice! - mrdoob

Oh man, I didn't know you guys released your tools. I'm a big fan of your stuff -- awesome to see such polished prods on the web. Happy to have helped enable some amazing work! - daeken

List of known nin projects

• Ninjacon 2016: Sea Shark Invtro
• Everything is Fashion
• Hold Kjæft
• Heatseeker
• Inakuwa Oasis
• Stars and boxes
• Crankwork Steamfist
• What Are You Syncing About?
• Zeven
• No Invitation
• Pinky Frinky
• Look Closer
• Neon Fantasy
• Flat Shade Society