API Docs for: 0.7.0

STLModel

Extends Model
Module: models
Parent Module: xeogl

An STLModel is a Model that's loaded from an STL file.

Overview

  • An STL (“StereoLithography”) file is a triangular representation of a 3-dimensional surface geometry. The surface is tessellated logically into a series of triangles. Each facet is described by a perpendicular direction and three points representing the vertices (corners) of the triangle.
  • An STLModel is a container of Components that loads itself from an STL file.
  • It begins loading as soon as you set its src property to the location of a valid STL file.
  • You can set src to a new file path at any time, which causes the STLModel to clear itself and load components from the new file.
  • For binary STL, has the option to create a separate Entity for each group of faces that share the same vertex colors. This allows us to treat STL models as parts assemblies.
  • Can be configured to automatically smooth STL models by converting their face-oriented normals to vertex-oriented.

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.

Examples

Usage

Loading STL

Load an STL file by creating an STLModel:

var model = new xeogl.STLModel({
    id: "myModel",
    src: "models/stl/F1Concept.stl",

    // Some example loading options (see "Options" below)
    smoothNormals: true,
    smoothNormalsAngleThreshold: 45
});

An STLModel 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 STLModel begins loading the STL file immediately.

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

model.on("loaded", function() {
       // STLModel 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 STL file, you can dynamically update src:

model.src = "models/stl/F1Concept.stl"

That will apply whatever options were specified to the constructor.

Parsing STL

If we have STL data in memory, then we can parse it directly into an existing STLModel instance using the static parse method:

xeogl.STLModel.parse(model, stlData, {

   // Some example parsing options (see "Options" below)
    smoothNormals: true,
    smoothNormalsAngleThreshold: 45,
    combineGeometry: true,
    quantizeGeometry: true
});

That's asynchronous because STL is self-contained and does not need to load any external assets.

Options

The following options may be specified when loading or parsing STL:

Option Type Range Default Value Description
quantizeGeometry Boolean true When true, quantizes geometry to reduce memory and GPU bus usage (see Geometry).
combineGeometry Boolean true When true, internally combines geometry vertex buffers to improve rendering performance (see Geometry).
smoothNormals Boolean false When true, automatically converts face-oriented normals to vertex normals for a smooth appearance. See Smoothing Normals.
smoothNormalsAngleThreshold Number (degrees) [0..180] 20 See Smoothing Normals.
backfaces Boolean true When true, allows visible backfaces, wherever specified in the STL. When false, ignores backfaces.
ghost Boolean false When true, ghosts all the model's Entities (see Entity and EmphasisMaterial).
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 EmphasisMaterial).
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.
splitEntities Boolean true When true, creates a separate Entity for each group of faces that share the same vertex colors. Only works with binary STL.

Smoothing Normals

As mentioned above, providing a smoothNormals flag to the constructor gives our STLModel a smooth appearance. Triangles in STL are disjoint, where each triangle has its own separate vertex positions, normals and (optionally) colors. This means that you can have gaps between triangles. Normals for each triangle are perpendicular to the triangle's surface, which gives the model a faceted appearance by default.

The smoothNormals flag causes the STLModel to recalculate its normals, so that each normal's direction is the average of the orientations of the triangles adjacent to its vertex. When smoothing, each vertex normal is set to the average of the orientations of all other triangles that have a vertex at the same position, excluding those triangles whose direction deviates from the direction of the vertice's triangle by a threshold given in smoothNormalsAngleThreshold. This makes smoothing robust for hard edges, which you can see on the cylindrical objects in one of the examples:

Note how the rim is smooth, yet the there is still a sharp edge adjacent to the flat portions.

Finding STLModels in Scenes

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

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

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

We can also get all the STLModels in a Scene, using the Scene's types map:

var stlModels = xeogl.scene.types["xeogl.STLModel"];

model = stlModels["myModel"];

Finding loaded Entities

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

Let's highlight an Entity in our STLModel:

var entities = scene.entities;

entities["myModel#1"].highlighted = true;

An STLModel also has an ID map of the components within it. Let's highlight an Entities:

model.components["myModel#1"].highlighted = true;

An STLModel also has a map containing just the Entities:

model.entities["myModel#1"].highlighted = true;

TODO: ID format description

Transforming an STLModel

An STLModel lets us transform its Entities as a group.

We can attach a modeling Transform, 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 STLModel 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.STLModel({
    src: "models/stl/F1Concept.stl",
    transform: {
       type: "xeogl.Translate",
       xyz: [-35, 0, 0],
       parent: {
           type: "xeogl.Rotate",
           xyz: [0, 1, 0],
           angle: 45
       }
    }
});

Getting the World-space boundary of an STLModel

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 STLModel's Transform is updated,
  • components are added or removed, or
  • the STLModel 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 an STLModel

model.clear();

Destroying an STLModel

model.destroy();

Constructor

STLModel

(
  • [scene]
  • [cfg]
)

Parameters:

  • [scene] Scene optional

    Parent Scene - creates this STLModel 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 STLModel.

    • [src] String optional

      Path to an STL file. You can set this to a new file path at any time, which will cause the

    • [quantizeGeometry=true] optional

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

    • [combineGeometry=true] optional

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

    • [smoothNormals=false] Boolean optional

      When true, automatically converts face-oriented normals to vertex normals for a smooth appearance - see Smoothing Normals.

    • [smoothNormalsAngleThreshold=20] Number optional
    • [backfaces=false] optional

      When true, allows visible backfaces, wherever specified in the STL. When false, ignores backfaces.

    • [ghosted=false] Boolean optional

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

    • [highlighted=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.

    • [transform] Number | String | Transform optional

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

    • [splitEntities=true] Boolean optional

      When true, creates a separate Entity for each group of faces that share the same vertex colors. Only works with binary STL.|

Methods

add

(
  • component
)

Inherited from Model: src/models/model.js:375

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]
)

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:567

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:702

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.

load

(
  • model
  • src
  • options
  • [ok]
  • [error]
)
static

Loads STL from a URL into a Model.

Parameters:

  • model Model

    Model to load into.

  • src String

    Path to STL file.

  • options Object

    Loading options.

  • [ok] Function optional

    Completion callback.

  • [error] Function optional

    Error callback.

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

parse

(
  • model
  • data
  • [options]
)
static

Parses STL into a Model.

Parameters:

  • model Model

    Model to parse into.

  • data ArrayBuffer

    The STL data.

  • [options] Object optional

    Parsing options

    • [basePath] String optional

      Base path path to find external resources on, if any.

    • [loadBuffer] String optional

      Callback to load buffer files.

removeAll

()

Inherited from Model: src/models/model.js:603

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

aabb

Float32Array final

Inherited from Model: src/models/model.js:762

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:294

The Components within this Model, mapped to their IDs.

Fires an Model/updated:event event on change.

culled

Boolean

Inherited from Model: src/models/model.js:853

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

Default: false

destroyed

Boolean

True as soon as this Component has been destroyed

entities

String:Entity

Inherited from Model: src/models/model.js:334

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

ghosted

Boolean

Inherited from Model: src/models/model.js:877

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

Default: false

highlighted

Boolean

Inherited from Model: src/models/model.js:901

Flag which indicates if this Model's Entities are rendered with highlighted 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:304

The number of Components within this Model.

outlined

Boolean

Inherited from Model: src/models/model.js:949

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

Default: false

scene

Scene final

The parent Scene that contains this Component.

selected

Boolean

Inherited from Model: src/models/model.js:925

Flag which indicates if this Model's Entities are rendered as selected.

Default: false

src

String

Path to an STL file.

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

Fires a loaded event when the STL 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:721

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:283

JavaScript class name for this Component.

types

String:{String:xeogl.Component}

Inherited from Model: src/models/model.js:312

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:829

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

Default: true

Events

added

Inherited from Model: src/models/model.js:528

Fired whenever an individual Component is added to this Model.

Event Payload:

boundary

Inherited from Model: src/models/model.js:985

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 STLModel fails to load the STL file specified by src.

Event Payload:

  • msg String

    Description of the error

loaded

Fired whenever this STLModel has finished loading components from the STL file specified by src.

removed

Inherited from Model: src/models/model.js:690

Fired whenever an individual Component is removed from this Model.

Event Payload:

transform

Inherited from Model: src/models/model.js:739

Fired whenever this Model's transform property changes.

Event Payload:

  • value Object

    The property's new value