API Docs for: 0.7.0

SceneJSModel

Extends Geometry
Module: models
Parent Module: xeogl

A SceneJSModel is a Model that imports content from the JSON-based SceneJS scene definition format.

Overview

  • A SceneJSModel is a container of Components that loads itself from a SceneJS scene definition, given as either a JSON file or a JavaScript object (POJO).
  • It begins loading as soon as you either set its src property to the location of a valid SceneJS JSON file, or set its data property to a valid POJO.
  • You can set these properties to new values at any time, which causes the SceneJSModel to clear itself and load fresh components.
  • Can be configured to do a best-effort conversion of SceneJS Phong materials into xeogl's PBR PBRMetalness or SpecularMaterials.

It inherits these capabilities from its Model base class:

  • Allows you to access and manipulate the components within it.
  • Can be transformed within World-space by attaching it to a Transform.
  • Provides its World-space boundary as a Boundary3D.

SceneJS Support

SceneJSModel was developed to import the Tron Tank model. As such, it only imports a limited subset of the SceneJS scene definition API. Use with caution and be prepared to fix and contribute missing functionality!

SceneJS nodes supported so far:

  • "node"
  • "rotate"
  • "translate"
  • "scale"
  • "material"
  • "texture"
  • "fresnel"
  • "flags"
  • "geometry"
  • "layer"
  • "stage"

Unsupported API features include:

  • Lights
  • Cameras
  • Shared node cores
  • SceneJS plugins

Examples

Usage

Loading a POJO scene definition

The simplest way to import SceneJS content is by setting a POJO on the SceneJSModel's data property:

var pojoModel = new xeogl.SceneJSModel({
       id: "myModel",

       // Our POJO scene definition
       data: {
           type: "node",
           nodes: [
               {
                   type: "rotate",
                   id: "myRotate",
                   nodes: [
                       {
                           type: "geometry",
                           id: "boxEntity",
                           primitive: "triangles",
                           positions: [
                               2, 2, 2, -2, 2, 2, -2, -2, 2, 2, -2, 2, 2, 2, 2, 2, -2,
                               2, 2, -2, -2, 2, 2, -2, 2, 2, 2, 2, 2, -2, -2, 2, -2,
                               -2, 2, 2, -2, 2, 2, -2, 2, -2, -2, -2, -2, -2, -2, 2,
                               -2, -2, -2, 2, -2, -2, 2, -2, 2, -2, -2, 2, 2, -2, -2,
                               -2, -2, -2, -2, 2, -2, 2, 2, -2
                           ],
                           normals: [
                               0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1,
                               0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, -1, 0,
                               0, -1, 0, 0, -1, 0, 0, -1, 0, 0, 0, -1, 0, 0, -1, 0, 0,
                              -1, 0, 0, -1, 0, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1
                           ],
                           uv: [
                               5, 5, 0, 5, 0, 0, 5, 0, 0, 5, 0, 0, 5, 0, 5, 5,
                               5, 0, 5, 5, 0, 5, 0, 0, 5, 5, 0, 5, 0, 0, 5, 0,
                               0, 0, 5, 0, 5, 5, 0, 5, 0, 0, 5, 0, 5, 5, 0, 5
                           ],
                           indices: [
                               0, 1, 2, 0, 2, 3, 4, 5, 6, 4, 6, 7, 8, 9, 10, 8, 10, 11,
                               12, 13, 14, 12, 14, 15, 16, 17, 18, 16, 18, 19, 20, 21,
                               22, 20, 22, 23
                           ]
                       }
                   ]
               }
           ]
       }
    });

// Set camera position
var camera = pojoModel.scene.camera;
camera.eye = [0, 0, -25];
camera.look = [0, 0, 0];
camera.up = [0, 1, 0];

Finding components

Our SceneJSModel has now created various xeogl components within itself, which we can find by their IDs. In this particular example, our POJO has a SceneJS "rotate" node with ID "myRotate". Our SceneJSModel parsed that into a Rotate component with ID "myModel.myRotate".

To see what components our SceneJSModel created, we can drop this expression into the browser's JavaScript debug console (we're using Chrome here):

pojoModel.types;

The result is the value of the SceneJSModel's types map, which contains its xeogl components, mapped to their types:

Here we've expanded the Rotate components, and we can see our Rotate. Note that its ID is prefixed with the ID of the SceneJSModel.

Let's get that Rotate from our SceneJSModel's components map and set it spinning:

var rotate = pojoModel.components["myModel.myRotate"];

pojoModel.scene.on("tick", function() {
   rotate.angle += 0.2;
});

Loading a JSON scene definition

As shown in the example below, we can also import a SceneJS scene definition from a JSON file (eg. tronTank.json). Note that we need to wait for the SceneJSModel's loaded event before we can access its components. In this example we're also showing how a SceneJSModel can be attached to a modeling Transform hierarchy to transform it within World space (see Model).

// Import SceneJS JSON model
var tankModel = new xeogl.SceneJSModel({
       id: "tankModel",

       // Path to our JSON scene definition file
       src: "models/scenejs/tronTank.json",

       // We can also bolt on a hierarchy of modeling transforms,
       // to transform the entire SceneJSModel in World space
       transform: new xeogl.Rotate({
           xyz: [0, 1, 0],
           angle: 0,
           parent: new xeogl.Translate({
               xyz: [0, 0, 0]
           })
       })
    });

// Once our SceneJSModel has loaded, we can access its components
tankModel.on("loaded", function() {

       tankModel.components["tankModel.gunDir"].angle = gunDir;

       // Set camera position
       var camera = tankModel.scene.camera;
       camera.eye = [0, 0, -70];
       camera.look = [0, 0, 0];
       camera.up = [0, 1, 0];
   });

Converting materials to PBR

var pbrSpecularTankModel = new xeogl.SceneJSModel({
   src: "models/scenejs/tronTank.json",
   materialWorkflow: "SpecularMaterial"
});
var pbrMetalnessTankModel = new xeogl.SceneJSModel({
   src: "models/scenejs/tronTank.json",
   materialWorkflow: "MetallicMaterial"
});

Constructor

SceneJSModel

(
  • [scene]
  • [cfg]
)

Parameters:

  • [scene] Scene optional

    Parent Scene - creates this SceneJSModel in the default Scene when omitted.

  • [cfg] optional

    Configs

    • [id] String optional

      Optional ID, unique among all components in the parent Scene, generated automatically when omitted.

    • [meta] String:Object optional

      Optional map of user-defined metadata to attach to this SceneJSModel.

    • [materialWorkflow] String optional

      Selects material workflow - "classic" | "pbrMatalness" | "pbrSpecular"

    • [src] String optional

      Path to a SceneJS JSON scene description file.

    • [data] String optional

      Path to a SceneJS JSON scene description file.

Methods

create

(
  • [cfg]
)

Convenience method for creating a Component within this Component's Scene.

The method is given a component configuration, like so:

var material = myComponent.create({
     type: "xeogl.PhongMaterial",
     diffuse: [1,0,0],
     specular: [1,1,0]
}, "myMaterial");

Parameters:

  • [cfg] optional

    Configuration for the component instance.

Returns:

:

destroy

()

Destroys this component.

Fires a destroyed event on this Component.

Automatically disassociates this component from other components, causing them to fall back on any defaults that this component overrode on them.

TODO: describe effect with respect to #create

error

(
  • message
)

Logs an error for this component to the JavaScript console.

The console message will have this format: [ERROR] [<component type> =<component id>: <message>

Also fires the message as an error event on the parent Scene.

Parameters:

  • message String

    The message to log

fire

(
  • event
  • value
  • [forget=false]
)

Fires an event on this component.

Notifies existing subscribers to the event, optionally retains the event to give to any subsequent notifications on the event as they are made.

Parameters:

  • event String

    The event type name

  • value Object

    The event parameters

  • [forget=false] Boolean optional

    When true, does not retain for subsequent subscribers

hasSubs

(
  • event
)
Boolean

Returns true if there are any subscribers to the given event on this component.

Parameters:

  • event String

    The event

Returns:

Boolean:

True if there are any subscribers to the given event on this component.

isType

(
  • type
)
Boolean

Tests if this component is of the given type, or is a subclass of the given type.

The type may be given as either a string or a component constructor.

This method works by walking up the inheritance type chain, which this component provides in property superTypes, returning true as soon as one of the type strings in the chain matches the given type, of false if none match.

Examples:

var myRotate = new xeogl.Rotate({ ... });

myRotate.isType(xeogl.Component); // Returns true for all xeogl components
myRotate.isType("xeogl.Component"); // Returns true for all xeogl components
myRotate.isType(xeogl.Rotate); // Returns true
myRotate.isType(xeogl.Transform); // Returns true
myRotate.isType("xeogl.Transform"); // Returns true
myRotate.isType(xeogl.Entity); // Returns false, because xeogl.Rotate does not (even indirectly) extend xeogl.Entity

Parameters:

  • type String | Function

    Component type to compare with, eg "xeogl.PhongMaterial", or a xeogl component constructor.

Returns:

Boolean:

True if this component is of given type or is subclass of the given type.

log

(
  • message
)

Logs a console debugging message for this component.

The console message will have this format: [LOG] [<component type> <component id>: <message>

Also fires the message as a log event on the parent Scene.

Parameters:

  • message String

    The message to log

off

(
  • handle
)

Cancels an event subscription that was previously made with on or once.

Parameters:

  • handle String

    Publication handle

on

(
  • event
  • callback
  • [scope=this]
)
String

Subscribes to an event on this component.

The callback is be called with this component as scope.

Parameters:

  • event String

    The event

  • callback Function

    Called fired on the event

  • [scope=this] Object optional

    Scope for the callback

Returns:

String:

Handle to the subscription, which may be used to unsubscribe with {@link #off}.

once

(
  • event
  • callback
  • [scope=this]
)

Subscribes to the next occurrence of the given event, then un-subscribes as soon as the event is handled.

This is equivalent to calling on, and then calling off inside the callback function.

Parameters:

  • event String

    Data event to listen to

  • callback Function(data)

    Called when fresh data is available at the event

  • [scope=this] Object optional

    Scope for the callback

warn

(
  • message
)

Logs a warning for this component to the JavaScript console.

The console message will have this format: [WARN] [<component type> =<component id>: <message>

Also fires the message as a warn event on the parent Scene.

Parameters:

  • message String

    The message to log

Properties

aabb

Float32Array final

Local-space axis-aligned 3D boundary (AABB) of this geometry.

The AABB is represented by a six-element Float32Array containing the min/max extents of the axis-aligned volume, ie. [xmin, ymin,zmin,xmax,ymax, zmax].

colors

Float32Array

The Geometry's vertex colors.

Default: null

combined

Boolean final

Indicates if this Geometry is combined.

Combination is an internally-performed optimization which combines positions, colors, normals and UVs into the same WebGL vertex buffers with other Geometries, in order to reduce the number of buffer binds performed per frame.

Default: false

data

A SceneJS POJO scene definition.

Update this at any time to clear and re-import content.

Fires a data event on change.

destroyed

Boolean

True as soon as this Component has been destroyed

id

String final

Unique ID for this Component within its parent Scene.

indices

Uint16Array | Uint32Array final

The Geometry's indices.

If xeogl.WEBGL_INFO.SUPPORTED_EXTENSIONS["OES_element_index_uint"] is true, then this can be a Uint32Array, otherwise it needs to be a Uint16Array.

Default: null

isDefault

Boolean

Indicates whether this is one of the Scene's built-in Components.

materialWorkflow

Selects which xeogl material type to create from each SceneJS Phong material.

Causes the SceneJSModel to attempt a best-effort conversion.

Update this at any time to reconvert the materials.

Fires a SceneJSModel/materialWorkFlow:event event on change.

metadata

Object

Arbitrary, user-defined metadata on this component.

normals

Float32Array

The Geometry's vertex normals.

Default: null

obb

Float32Array final

Local-space oriented 3D boundary (OBB) of this geometry.

The OBB is represented by a 32-element Float32Array containing the eight vertices of the box, where each vertex is a homogeneous coordinate having [x,y,z,w] elements.

positions

Float32Array

The Geometry's vertex positions.

Default: null

primitive

String

The Geometry's primitive type.

Valid types are: 'points', 'lines', 'line-loop', 'line-strip', 'triangles', 'triangle-strip' and 'triangle-fan'.

Default: "triangles"

quantized

Boolean final

Indicates if this Geometry is quantized.

Compression is an internally-performed optimization which stores positions, colors, normals and UVs in quantized and oct-encoded formats for reduced memory footprint and GPU bus usage.

Quantized geometry may not be updated.

Default: false

scene

Scene final

The parent Scene that contains this Component.

src

String

Path to the SceneJS JSON scene description file.

Update this at any time to clear and re-import content.

Fires a src event on change.

superTypes

Array of String final

An array of strings that indicates the chain of super-types within this component's inheritance hierarchy.

For example, if this component is a Rotate, which extends Transform, which in turn extends Component, then this property will have the value:

["xeogl.Component", "xeogl.Transform"]
                    

Note that the chain is ordered downwards in the hierarchy, ie. from super-class down towards sub-class.

type

String final

JavaScript class name for this Component.

For example: "xeogl.AmbientLight", "xeogl.ColorTarget", "xeogl.Lights" etc.

uv

Float32Array

The Geometry's UV coordinates.

Default: null

Events

boundary

Fired whenever this Geometry's boundary changes.

Get the latest boundary from the Geometry's aabb and obb properties.

data

Fired whenever this SceneJSModel's data property changes.

Event Payload:

  • value Object

    The property's new value

destroyed

Fired when this Component is destroyed.

loaded

Fired whenever this SceneJSModel has finished loading the SceneJS JSON file specified by src.

materialWorkflow

Fired whenever this SceneJSModel's materialWorkflow property changes.

Event Payload:

  • value Object

    The property's new value

src

Fired whenever this SceneJSModel's src property changes.

Event Payload:

  • value Object

    The property's new value