API Docs for: 1.0.0

GLTFModel

Extends Model
Module: models
Parent Module: xeogl

A GLTFModel is a Model loaded from a glTF file.

Overview

  • A GLTFModel is a container of Components that loads itself from a glTF file.
  • It begins loading as soon as you set its src property to the location of a valid glTF file.
  • You can set src to a new file path at any time, which causes the GLTFModel to clear itself and load components from the new file.

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.

Supported glTF 2.0 features

So far, GLTFModel loads only geometry, materials and modeling transform hierarchies, without animations. It does not load cameras or lights because its purpose is to import models into environments that have already been created using the xeogl API.

In addition to glTF's core metal-roughness material workflow, GLTFModel also supports two material extensions:

Usage

Loading glTF

Load a glTF file by creating a GLTFModel:

var gearbox = new xeogl.GLTFModel({
  id: "gearbox",
  src: "models/gltf/gearbox/gearbox_assy.gltf"
});

A GLTFModel prefixes its own ID to those of its components. Its ID is optional and defaults to the value of src. In this example we're providing our own short ID, however, in order to keep the component IDs short and easy to use.

The GLTFModel begins loading the glTF file immediately. Bind a callback to be notified when the file has loaded (which fires immediately if already loaded):

gearbox.on("loaded", function() {
       // GLTFModel has loaded!
   });

You can also bind a callback to fire if loading fails:

gearbox.on("error", function(msg) {
       // Error occurred
   });

To switch to a different glTF file, simply update src:

gearbox.src = "models/gltf/Buggy/glTF/Buggy.gltf"

Accessing components

Once the GLTFModel has loaded, its Scene will contain various components that represent the elements of the glTF file. We'll now access some of those components by ID, to query and update them programmatically.

Transforms

Let's reposition one of the Entities in our GLTFModel. We'll get the Transform that positions our target Entity, in this case a gear. Then we'll update its matrix to translate it ten units along the negative Z-axis.

var transform = gearbox.scene.components["gearbox#n274017_gear_53t-node.transform"];

transform.matrix = xeogl.math.translationMat4v([0,0,-10]);

Note the format of the Transform's ID:

<GLTFModel ID>#<glTF node ID>.transform

From left to right, the format contains the GLTFModel's ID, the ID of the glTF node that contains the transform, then "transform", to distinguish it from the IDs of any other components loaded from elements on the same glTF node.

Entities

Let's make our gear Entity invisible:

var gear53 = gearbox.scene.components["gearbox#n274017_gear_53.entity.0"];

gear53.visible = false;

Note the format of the Entity's ID: <GLTFModel ID>#<glTF node ID>.entity.<glTF mesh index>

A glTF scene node may contain multiple meshes, and for each of those xeogl will create an individual Entity. As before, the part before the hash is the ID of the GLTFModel, which is then followed by the ID of the glTF node, then "entity" to signify that this is an Entity ID, then finally an index to differentiate the Entity from those loaded from other meshes on the same glTF node.

Examples

Constructor

GLTFModel

(
  • [scene]
  • [cfg]
)

Parameters:

  • [scene] Scene optional

    Parent Scene - creates this GLTFModel 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 GLTFModel.

    • [src] String optional

      Path to a glTF file. You can set this to a new file path at any time, which will cause the GLTFModel to load components from the new file (after first destroying any components loaded from a previous file path).

    • [transform] Number | String | Transform optional

      A Local-to-World-space (modelling) Transform to attach to this GLTFModel. Must be within the same Scene as this GLTFModel. Internally, the given Transform will be inserted above each top-most Transform that the GLTFModel attaches to its Entities.

Methods

add

(
  • component
)

Inherited from Model: src/models/model.js:328

Adds a Component or subtype to this Model.

The Component(s) may be specified by ID, instance, JSON definition or type.

See class comment for usage examples.

The Components must be in the same Scene as this Model.

Fires an added event.

Parameters:

  • component Number | String | | Component

    ID, definition or instance of a Component type or subtype.

create

(
  • [cfg]
  • [instanceId]
)

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

You would typically use this method to conveniently instantiate components that you'd want to share (ie. "instance") among your Entities.

The method is given a component type, configuration and optional instance ID, like so:

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

The first time you call this method for the given type and instanceId, this method will create the PhongMaterial, passing the given attributes to the component's constructor.

If you call this method again, specifying the same type and instanceId, the method will return the same component instance that it returned the first time, and will ignore the new configuration:

var material2 = component.create({ type: "xeogl.PhongMaterial", specular: [1,1,0] }, "myMaterial");

So in this example, our PhongMaterial will continue to have the red specular and diffuse color that we specified the first time.

Each time you call this method with the same type and instanceId, the Scene will internally increment a reference count for the component instance.

Parameters:

  • [cfg] optional

    Configuration for the component instance - only used if this is the first time you are getting the component, ignored when reusing an existing instance.

  • [instanceId] String | Number optional

    Identifies the shared component instance. Note that this is not used as the ID of the component - you can specify the component ID in the cfg parameter.

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

destroyAll

()

Inherited from Model: src/models/model.js:517

Destroys all Components in this Model.

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.

iterate

(
  • callback
  • [scope=this]
)

Inherited from Model: src/models/model.js:611

Iterates with a callback over the Components in this Model.

Parameters:

  • callback Function

    Callback called for each Component.

  • [scope=this] Object optional

    Optional scope for the callback, defaults to this Model.

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

removeAll

()

Inherited from Model: src/models/model.js:553

Removes all Components from this Model.

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

components

String:Component

Inherited from Model: src/models/model.js:256

The Components within this Model, mapped to their IDs.

Fires an Model/updated:event event on change.

destroyed

Boolean

True as soon as this Component has been destroyed

entities

String:Entity

Inherited from Model: src/models/model.js:296

The Entity component instances within this Model, mapped to their IDs.

id

String final

Unique ID for this Component within its parent Scene.

isDefault

Boolean

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

json

JSON final

JSON object containing the state of this Component.

metadata

Object

Arbitrary, user-defined metadata on this component.

numComponents

Number

Inherited from Model: src/models/model.js:266

The number of Components within this Model.

scene

Scene final

The parent Scene that contains this Component.

src

String

Path to a glTF file.

You can set this to a new file path at any time (except while loading), which will cause the GLTFModel to load components from the new file (after first destroying any components loaded from a previous file path).

Fires a src event on change.

src

String

Path to a glTF file.

You can set this to a new file path at any time (except while loading), which will cause the GLTFModel to load components from the new file (after first destroying any components loaded from a previous file path).

Fires a src event on change.

string

String final

Inherited from Component but overwritten in src/component.js:1065

String containing the serialized JSON state of this Component.

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.

transform

Transform

Inherited from Model: src/models/model.js:630

The Local-to-World-space (modelling) Transform attached to this Model.

Must be within the same Scene as this Model.

Internally, the given Transform will be inserted above each top-most Transform that the Model attaches to its Entities.

Fires an transform event on change.

type

String final

Inherited from Component but overwritten in src/models/model.js:245

JavaScript class name for this Component.

types

String:{String:xeogl.Component}

Inherited from Model: src/models/model.js:274

A map of maps; for each Component type in this Model, a map to IDs to Component instances, eg.

"xeogl.Geometry": {
                      "alpha": <xeogl.Geometry>,
                      "beta": <xeogl.Geometry>
                    },
                    "xeogl.Rotate": {
                      "charlie": <xeogl.Rotate>,
                      "delta": <xeogl.Rotate>,
                      "echo": <xeogl.Rotate>,
                    },
                    //...
                    

worldBoundary

Boundary3D final

Inherited from Model: src/models/model.js:671

World-space 3D boundary enclosing all the components in this Model.

If you call destroy on this boundary, then this property will be assigned to a fresh Boundary3D instance next time you reference it.

Events

added

Inherited from Model: src/models/model.js:476

Fired whenever an individual Component is added to this Model.

Event Payload:

destroyed

Fired when this Component is destroyed.

error

Fired whenever this GLTFModel fails to load the glTF file specified by src.

Event Payload:

  • msg String

    Description of the error

error

Fired whenever this GLTFModel fails to load the glTF file specified by src.

Event Payload:

  • msg String

    Description of the error

loaded

Fired whenever this GLTFModel has finished loading components from the glTF file specified by src.

loaded

Fired whenever this GLTFModel has finished loading components from the glTF file specified by src.

removed

Inherited from Model: src/models/model.js:599

Fired whenever an individual Component is removed from this Model.

Event Payload:

src

Fired whenever this GLTFModel's src property changes.

Event Payload:

  • value Object

    The property's new value

src

Fired whenever this GLTFModel's src property changes.

Event Payload:

  • value Object

    The property's new value

transform

Inherited from Model: src/models/model.js:648

Fired whenever this Model's transform property changes.

Event Payload:

  • value Object

    The property's new value