API Docs for: 0.7.0

SpotLight

Extends Component
Module: lighting
Parent Module: xeogl

A SpotLight defines a positional light source that originates from a single point and eminates in a given direction, to illuminate Entities.

Overview

  • SpotLights are grouped, along with other light source types, within a Lights component, which belongs to a Scene.
  • SpotLights have a position and direction.
  • SpotLights may be defined in either World or View coordinate space. When in World-space, their positions are relative to the World coordinate system, and will appear to move as the Camera moves. When in View-space, their positions are relative to the View coordinate system, and will behave as if fixed to the viewer's head as the Camera moves.
  • SpotLights have constantAttenuation, linearAttenuation and quadraticAttenuation factors, which indicate how their intensity attenuates over distance.
  • A SpotLight can also have a Shadow component, to configure it to cast a shadow.

Examples

TODO

Usage

In the example below we'll customize the default Scene's light sources, defining an AmbientLight and a couple of SpotLights, then create a Phong-shaded box entity.


// We're using the default xeogl Scene
// Get Scene's Lights
var lights = xeogl.scene.lights;

// Customize the light sources
lights.lights = [
    new xeogl.AmbientLight({
        color: [0.8, 0.8, 0.8],
        intensity: 0.5
    }),
    new xeogl.SpotLight({
        pos: [0, 100, 100],
        dir: [0, -1, 0],
        color: [0.5, 0.7, 0.5],
        intensity: 1
        constantAttenuation: 0,
        linearAttenuation: 0,
        quadraticAttenuation: 0,
        space: "view"
    }),
    new xeogl.PointLight({
        pos: [0, 100, 100],
        dir: [0, -1, 0],
        color: [0.5, 0.7, 0.5],
        intensity: 1
        constantAttenuation: 0,
        linearAttenuation: 0,
        quadraticAttenuation: 0,
        space: "view"
    })
];

// Create box entity
new xeogl.Entity({
   material: new xeogl.PhongMaterial({
       ambient: [0.5, 0.5, 0.5],
       diffuse: [1,0.3,0.3]
   }),
   geometry: new xeogl.BoxGeometry()
});

Constructor

SpotLight

(
  • [scene]
  • [cfg]
)

Parameters:

  • [scene] Scene optional

    Parent Scene, creates this SpotLight within the default Scene when omitted

  • [cfg] optional

    The SpotLight configuration

    • [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 SpotLight.

    • [pos=[ 1.0, 1.0, 1.0 ]] Float32Array optional

      Position, in either World or View space, depending on the value of the space parameter.

    • [dir=[ 0.0, -1.0, 0.0 ]] Float32Array optional

      Direction in which this Spotlight is shining, in either World or View space, depending on the value of the space parameter.

    • [color=[0.7, 0.7, 0.8 ]] Float32Array optional

      Color of this SpotLight.

    • [intensity=1.0] Number optional

      Intensity of this SpotLight.

    • [constantAttenuation=0] Number optional

      Constant attenuation factor.

    • [linearAttenuation=0] Number optional

      Linear attenuation factor.

    • [quadraticAttenuation=0] Number optional

      Quadratic attenuation factor.

    • [space="view"] String optional

      The coordinate system this SpotLight is defined in - "view" or "world".

    • [shadow=false] Boolean optional

      Flag which indicates if this SpotLight casts a shadow.

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

color

Float32Array

The color of this SpotLight.

Fires a color event on change.

Default: [0.7, 0.7, 0.8]

constantAttenuation

Number

The constant attenuation factor for this SpotLight.

Fires a constantAttenuation event on change.

Default: 0

destroyed

Boolean

True as soon as this Component has been destroyed

dir

Float32Array

The direction in which the light is shining.

Fires a dir event on change.

Default: [1.0, 1.0, 1.0]

id

String final

Unique ID for this Component within its parent Scene.

intensity

Number

The intensity of this SpotLight.

Fires a intensity event on change.

Default: 1.0

isDefault

Boolean

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

linearAttenuation

Number

The linear attenuation factor for this SpotLight.

Fires a linearAttenuation event on change.

Default: 0

metadata

Object

Arbitrary, user-defined metadata on this component.

pos

Array(Number)

The position of this SpotLight.

This will be either World- or View-space, depending on the value of space.

Fires a pos event on change.

Default: [1.0, 1.0, 1.0]

quadraticAttenuation

Number

The quadratic attenuation factor for this SpotLight.

Fires a quadraticAttenuation event on change.

Default: 0

scene

Scene final

The parent Scene that contains this Component.

shadow

Boolean

Flag which indicates if this SpotLight casts a shadow.

Fires a shadow event on change.

Default: false

space

String

Indicates which coordinate space this SpotLight is in.

Supported values are:

  • "view" - View space, aligned within the view volume as if fixed to the viewer's head
  • "world" - World space, fixed within the world, moving within the view volume with respect to camera

Fires a space event on change.

Default: "view"

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.

Events

color

Fired whenever this SpotLight's color property changes.

Event Payload:

  • value Object

    The property's new value

constantAttenuation

Fired whenever this SpotLight's constantAttenuation property changes.

Event Payload:

  • value Object

    The property's new value

destroyed

Fired when this Component is destroyed.

dir

Fired whenever this SpotLight's dir property changes.

Event Payload:

  • value Object

    The property's new value

intensity

Fired whenever this SpotLight's intensity property changes.

Event Payload:

  • value Object

    The property's new value

linearAttenuation

Fired whenever this SpotLight's linearAttenuation property changes.

Event Payload:

  • value Object

    The property's new value

pos

Fired whenever this SpotLight's pos property changes.

Event Payload:

  • value Object

    The property's new value

quadraticAttenuation

Fired whenever this SpotLight's quadraticAttenuation property changes.

Event Payload:

  • value Object

    The property's new value

shadow

Fired whenever this SpotLight's shadow property changes.

Event Payload:

  • value Object

    The property's new value

space

Fired whenever this SpotLight's space property changes.

Event Payload:

  • value Object

    The property's new value