API Docs for: 0.7.0

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 dynamic World-space axis-aligned boundary.

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:

Examples

Usage

Loading glTF

Load a glTF file by creating a GLTFModel:

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

A GLTFModel prefixes its own ID to those of its components. The ID is optional, but in this example we're providing our own custom ID.

The GLTFModel begins loading the glTF file immediately.

To bind a callback to be notified when the file has loaded (which fires immediately if already loaded):

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

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

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

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

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

Loading options

The following options may be specified when loading glTF:

Option Type Range Default Value Description
flattenTransforms Boolean true Flattens transform hierarchies to improve rendering performance.
lambertMaterials Boolean false When true, gives each Entity the same LambertMaterial and a colorize set the to diffuse color extracted from the glTF material. This is typically used for CAD models with huge amounts of objects, and will ignore textures.
quantizeGeometry Boolean true When true, quantizes geometry to reduce memory and GPU bus usage (see Geometry).
combineGeometry Boolean true When true, combines geometry vertex buffers to improve rendering performance (see Geometry).
backfaces Boolean true When true, allows visible backfaces, wherever specified in the glTF. When false, ignores backfaces.
ghost Boolean false When true, ghosts all the model's Entities (see Entity and GhostMaterial).
outline Boolean false When true, outlines all the model's Entities (see Entity and OutlineMaterial).
highlight Boolean false When true, highlights all the model's Entities (see Entity and HighlightMaterial).
ghostEdgeThreshold Number [0..180] 2 When ghosting, this is the threshold angle between normals of adjacent triangles, below which their shared wireframe edge is not drawn.
maxEntities Number Optional maximum number of Entity's to load.
included Function(entityId) null Optional callback to mask which Entity's are loaded. Entity will only be loaded when this callback returns `true for the given Entity ID.

Using the flattenTransforms option to load a glTF model while flattening its transform hierarchy:

var model = new xeogl.GLTFModel({
    id: "gearbox",
    src: "models/gltf/gearbox_conical/scene.gltf",
    flattenTransforms: true
});

Using the included option to load all entities except for those with IDs "gearbox#77.0" and "gearbox#79.0":

var model = new xeogl.GLTFModel({
    id: "gearbox",
    src: "models/gltf/gearbox_conical/scene.gltf",
    included: function(entityId) {
       return id !== ("gearbox#77.0") &&  (id !== "gearbox#79.0");
    }
});

Finding GLTFModels in Scenes

Our GLTFModel will now be registered by ID on its Scene, so we can now find it like this:

model = xeogl.scene.models["gearbox"];

That's assuming that we've created the GLTFModel in the default xeogl Scene, which we're doing in these examples.

Finding loaded Entities

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.

Let's highlight a couple of Entities in our GLTFModel:

var entities = scene.entities;

entities["gearbox77.0"].highlight = true;
entities["gearbox79.0"].highlight = true;

A GLTFModel also has ID maps of the components within it. Its components map contains all its Components in one big map:

model.components["gearbox77.0"].highlight = true;

while its entities map contains just the Entities:

model.entities["gearbox77.0"].highlight = true;

Note the format of the Entity IDs:

<GLTFModel ID>#<glTF node ID>.<glTF primitive index>

Within the glTF, a node's mesh may contain multiple primitives. For each primitive, xeogl will create a separate Entity. Within each Entity's ID, the part before the hash is the ID of the GLTFModel, followed by the ID of the node, then ".", then the index of the primitive within the mesh.

Transforming a GLTFModel

A GLTFModel lets us transform its Entities as a group.

We can attach a modeling Transform to our GLTFModel, as a either a configuration object or a component instance:

// Attach transforms as a configuration object:
model.transform = {
       type: "xeogl.Translate",
       xyz: [-35, 0, 0],
       parent: {
           type: "xeogl.Rotate",
           xyz: [0, 1, 0],
           angle: 45
       }
    };

// Attach our own transform instances:
model.transform = new xeogl.Translate({
       xyz: [-35, 0, 0],
       parent: new xeogl.Rotate({
           xyz: [0, 1, 0],
           angle: 45
       })
    });

We can also provide the Transform to the GLTFModel constructor, as either configuration objects or instances.

Here we'll provide a Transform hierarchy as a configuration object:

// Model internally instantiates our transform components:
var model = new xeogl.GLTFModel({
    src: "models/gltf/gearbox_conical/scene.gltf",
    transform: {
       type: "xeogl.Translate",
       xyz: [-35, 0, 0],
       parent: {
           type: "xeogl.Rotate",
           xyz: [0, 1, 0],
           angle: 45
       }
    }
});

Getting the World-space boundary of a GLTFModel

Get the World-space axis-aligned boundary like this:

model.on("boundary", function() {
   var aabb = model.aabb; //  [xmin, ymin,zmin,xmax,ymax, zmax]
   //...
});

We can also subscribe to changes to that boundary, which will happen whenever

  • the GLTFModel's Transform is updated,
  • components are added or removed, or
  • the GLTF model is reloaded from a different source,
  • the Geometries or Transforms of its Entities are updated.
model.on("boundary", function() {
   var aabb = model.aabb; // [xmin, ymin,zmin,xmax,ymax, zmax]
});

Clearing a GLTFModel

model.clear();

Destroying a GLTFModel

model.destroy();

Constructor

GLTFModel

(
  • [scene]
  • [cfg]
  • [flattenTransforms=true]
  • [lambertMaterials
  • [quantizeGeometry
  • [combineGeometry
  • [backfaces
  • [ghost=false]
  • [highlight=false]
  • [outline=false]
  • [ghostEdgeThreshold=2]
  • [maxEntities]
  • [included]
)

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

    • [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.

  • [flattenTransforms=true] Boolean optional

    Flattens transform hierarchies to improve rendering performance.

  • [lambertMaterials #crossLink "Entity"

    | Boolean | | false | When true, gives each }{{/crossLink}} the same {{#crossLink "LambertMaterial"}}{{/crossLink}} and a {{#crossLink "Entity/colorize:property"}}{{/crossLink}} set the to diffuse color extracted from the glTF material. This is typically used for CAD models with huge amounts of objects, and will ignore textures.|

  • [quantizeGeometry Object

    | Boolean | | true | When true, quantizes geometry to reduce memory and GPU bus usage. |

  • [combineGeometry Object

    | Boolean | | true | When true, combines geometry vertex buffers to improve rendering performance. |

  • [backfaces Object

    | Boolean | | true | When true, allows visible backfaces, wherever specified in the glTF. When false, ignores backfaces. |

  • [ghost=false] Boolean optional

    When true, sets all the Model's Entities initially ghosted. |

  • [highlight=false] Boolean optional

    When true, sets all the Model's Entities initially highlighted. |

  • [outline=false] Boolean optional

    When true, sets all the Model's Entities initially outlined. |

  • [ghostEdgeThreshold=2] Number optional

    When ghosting, this is the threshold angle between normals of adjacent triangles, below which their shared wireframe edge is not drawn. |

  • [maxEntities] Number optional

    Optional maximum number of Entity's to load. |

  • [included] Function optional

    Optional callback to mask which Entity's are loaded. Entity will only be loaded when this callback returns `true for the given Entity ID. | GLTFModel to load components from the new file (after first destroying any components loaded from a previous file path).

Methods

add

(
  • component
)

Inherited from Model: src/models/model.js:348

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.

canvasPosToLocalRay

(
  • camera
  • entity
  • canvasPos
  • localRayOrigin
  • localRayDir
)
static

Provided by the xeogl module.

Defined in src/math/mathRays.js:73

Transforms a Canvas-space position to an Entity's Local-space coordinate system, in the context of a Camera.

Parameters:

  • camera Camera

    The Camera.

  • entity Entity

    The Entity.

  • canvasPos Float32Array

    The Canvas-space position.

  • localRayOrigin Float32Array

    The Local-space ray origin.

  • localRayDir Float32Array

    The Local-space ray direction.

canvasPosToWorldRay

(
  • camera
  • canvasPos
  • worldRayOrigin
  • worldRayDir
)
static

Provided by the xeogl module.

Defined in src/math/mathRays.js:10

Transforms a Canvas-space position into a World-space ray, in the context of a Camera.

Parameters:

  • camera Camera

    The Camera.

  • canvasPos Float32Array

    The Canvas-space position.

  • worldRayOrigin Float32Array

    The World-space ray origin.

  • worldRayDir Float32Array

    The World-space ray direction.

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

destroyAll

()

Inherited from Model: src/models/model.js:538

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:632

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:574

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

worldRayToLocalRay

(
  • entity
  • worldRayOrigin
  • worldRayDir
  • localRayOrigin
  • localRayDir
)
static

Provided by the xeogl module.

Defined in src/math/mathRays.js:94

Transforms a ray from World-space to an Entity's Local-space coordinate system.

Parameters:

  • entity Entity

    The Entity.

  • worldRayOrigin Float32Array

    The World-space ray origin.

  • worldRayDir Float32Array

    The World-space ray direction.

  • localRayOrigin Float32Array

    The Local-space ray origin.

  • localRayDir Float32Array

    The Local-space ray direction.

Properties

aabb

Float32Array final

Inherited from Model: src/models/model.js:692

World-space axis-aligned 3D boundary (AABB) of this Model.

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].

components

String:Component

Inherited from Model: src/models/model.js:270

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:310

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

ghost

Boolean

Inherited from Model: src/models/model.js:786

Flag which indicates if this Model's Entities are rendered with ghost effect.

Default: false

highlight

Boolean

Inherited from Model: src/models/model.js:813

Flag which indicates if this Model's Entities are rendered with highlight effect.

Default: false

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.

metadata

Object

Arbitrary, user-defined metadata on this component.

numComponents

Number

Inherited from Model: src/models/model.js:280

The number of Components within this Model.

outline

Boolean

Inherited from Model: src/models/model.js:840

Flag which indicates if this Model's Entities are rendered with outline effect.

Default: false

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 loaded event when the glTF has loaded.

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:651

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:259

JavaScript class name for this Component.

types

String:{String:xeogl.Component}

Inherited from Model: src/models/model.js:288

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>,
                    },
                    //...
                    

visible

Boolean

Inherited from Model: src/models/model.js:759

Indicates whether this Model's Entities are visible or not.

Default: true

Events

added

Inherited from Model: src/models/model.js:499

Fired whenever an individual Component is added to this Model.

Event Payload:

boundary

Inherited from Model: src/models/model.js:879

Fired whenever this Model's World-space boundary changes.

Get the latest boundary from the Model's aabb property.

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

loaded

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

removed

Inherited from Model: src/models/model.js:620

Fired whenever an individual Component is removed from this Model.

Event Payload:

transform

Inherited from Model: src/models/model.js:669

Fired whenever this Model's transform property changes.

Event Payload:

  • value Object

    The property's new value